physics final exam
1. What term is used for "electricity at rest?"
-electrostatics
5. Exactly what is it that enables an object to do work?
-energy enables an object to do work
Comment on the warning sign shown in the sketch. (Figure 1)
...
kilocalorie
1000 calories
How far does a horse travel if it gallops at an average speed of 25 km/h for 30 min?
12.5 km
D
14) The source of electrons in an ordinary electrical circuit is A) a dry cell, wet cell or battery. B) the back emf of motors. C) the power station generator. D) the electrical conductor itself. E) none of these.
A
17) In a common dc circuit, electrons move at speeds of A) a fraction of a centimeter per second. B) many centimeters per second. C) the speed of a sound wave. D) the speed of light. E) none of these.
C
19) A balloon will stick to a wooden wall if the balloon is charged A) negatively. B) positively. C) either way. D) neither way.
B
19) Alternating current is normally produced by a A) battery. B) generator. C) both of these. D) neither of these.
fill in the blanks: newtons first law is often called the law of_____; newtons second law highlights the concepts of force, mass, and ______; and newtons third law is the law of ______ and _____
1st law: motion 2nd law: acceleration 3rd law: action and reaction
D
22) The electric field inside the dome of a Van de Graaff generator A) depends on the amount of charge on it. B) depends on its size. C) both of these. D) neither of these.
A
24) Modern automobile headlights are connected in A) parallel. B) perpendicular. C) series. D) none of these.
Speed of light (c)
300,000 km/s 300,000,000 m/s
E
31) An electrical diode is useful for A) storing electrical energy. B) boosting voltage. C) limiting current. D) voltage modification. E) changing ac to dc.
A
32) A negatively charged rod is brought near a metal can that rests on a wood table. You touch the opposite side of the can momentarily with your finger. The can is then A) positively charged. B) negatively charged. C) uncharged. D) charged the same as it was.
C
33) Every proton in the universe is surrounded by its own A) electric field. B) gravitational field. C) both of these. D) none of these.
sound travels
4 times faster in water than air and about 15 times faster in steel than in air
If a voltage of 6 V is impressed across the circuit in the preceding question and the voltage across the first lamp is 2 V, what is the voltage across the second lamp? Defend your answer.
4 volts. The sum of the voltages across each lamp must add up to the total voltage across both lamps.
A
4) A coulomb of charge that passes through a 6-volt battery is given A) 6 joules. B) 6 amperes. C) 6 ohms. D) 6 watts. E) 6 newtons.
B
40) As more lamps are put into a series circuit, the overall current in the power source A) increases. B) decreases. C) stays the same.
A
40) To be safe in the unlikely case of a lightning strike, it is best to be inside a building framed with A) steel. B) wood. C) both the same.
If the fundamental frequency of a note is 200 Hz, then what is the frequency of the second harmonic?
400 Hz
At what angle inside glass is light totally internally reflected? At what angle inside a diamond is light totally internally reflected?
43 degrees, 24.5 degrees
E
43) When we say an appliance "uses up electricity," we really are saying that A) current disappears. B) electric charges are dissipated. C) the main power supply voltage is lowered. D) electrons are taken out of the circuit and put somewhere else. E) electron kinetic energy is changed into heat.
A
43) You can touch a 100,000-volt Van de Graaff generator with little harm because although the voltage is high, the relatively small amount of charge means there is a relatively small amount of A) energy. B) electric field. C) polarization. D) conduction.
B
44) Compared to the resistance of two resistors connected in series, the same two resistors connected in parallel have A) more resistance. B) less resistance. C) the same resistance.
E
44) Two charges separated by one meter exert 1-N forces on each other. If the charges are pushed to 1/4 meter separation, the force on each charge will be A) 1 N. B) 2 N. C) 4 N. D) 8 N. E) 16 N.
D
45) If you plug an electric toaster rated at 110 V into a 220-V outlet, the current in the toaster will be about A) half what it should be. B) the same as if it were plugged into 110 V. C) more than twice what it should be. D) twice what it should be.
B
45) Two charges separated by one meter exert 1-N forces on each other. If the charges are pulled to 3-m separation distance, the force on each charge will be A) 0.33 N. B) 0.11 N. C) 0 N. D) 3 N. E) 9 N.
B
46) A 60-watt light bulb is connected to a 120-volt plug. What is the current in the light bulb? A) 0.25 A B) 0.5 A C) 2 A D) 4 A E) more than 4 A
B
8) The unit of electric charge, the coulomb, is the charge on A) one electron. B) a specific large number of electrons.
C
9) A wire carrying a current is normally charged A) negatively. B) positively. C) not at all.
What does a changing electric field induce?
A changing magnetic field. And vice versa.
0.75 seconds
A nurse counts 80 heartbeats in one minute. What is the period of one of the heart's beats?
Can a pair of vectors with unequal magnitudes ever add to zero? Can three unequal vectors add to zero? Defend your answers.
A pair of vectors can cancel only if they are equal in magnitude and opposite in direction. But three unequal vectors can combine to equal zero
When does light behave as a wave? When does it behave as a particle?
A photon behaves as a particle when its being emitted as an atom or absorbed by photographic film or other detectors and behaves as a wave in traveling from a source to the place where it is detected
How does a pigment affect light?
A pigment selectively absorbs some frequencies of light and transmits others.
Antinode
A point of maximum amplitude on a standing wave
Newton viewed the curving of the path of a planet as being caused by a force acting on the planet. How did Einstein view the curved path of a planet? A) Moving in curved 4-dimensional spacetime. B) Always at rest C) In a straight line called a geodesic D) In an ellipse
A) Moving in curved 4-dimensional spacetime.
38) Distant dark colored hills appear blue because that is the color of the A) atmosphere between the observer and the hills. B) selectively reflected light that reaches a distant observer. C) reflected light that survives scattering. D) sky that is reflected off the hills.
A) atmosphere between the observer and the hills.
44) On a planet where atmospheric gases are yellow, distant snow covered hills would look A) bluish. B) greenish. C) yellowish. D) reddish. E) untinted.
A) bluish.
32) The part of the electromagnetic spectrum most absorbed by water is A) infrared. B) lower frequencies in the visible. C) middle frequencies in the visible. D) higher frequencies in the visible. E) ultraviolet.
A) infrared.
1) Color depends on what characteristic of light? A) its frequency B) its amplitude C) both of these
A) its frequency
13) Magenta light is really a mixture of A) red and blue light. B) red and cyan light. C) red and yellow light. D) yellow and green light. E) none of these
A) red and blue light.
alternating current
AC repeatedly reverses direction
Credit for research in our knowledge of atomic spectra includes Johann Jacob Balmer. Walter Ritz. Johannes Rydberg. all of the above none of the above
All of the above
Why are all tides greatest at the time of a full Moon or new Moon?
At full Moon and new Moon, the tides from the Moon and the Sun add because they are in line with Earth
State Newton's law of universal gravitation in words. Then do the same with one equation. A) The force is proportional to the product of two masses and inversely proportional to the distance between their centers B) The force is proportional to the product of two masses and inversely proportional to the square of the distance between their centers. C) The force is proportional to the product of two masses and to the square of the distance between their centers D) The force is proportional to the product of two masses.
B) The force is proportional to the product of two masses and inversely proportional to the square of the distance between their centers
While a bullet is being fired within the rifle, how does the force exerted on the bullet compare to the force exerted on the rifle? A) The magnitude of the force acting on the bullet is just a little big greater than that acting on the rifle. B) The magnitude of the force acting on the bullet is equal to that acting on the rifle. C) The magnitude of the force acting on the bullet is much larger than that acting on the rifle.
B) The magnitude of the force acting on the bullet is equal to that acting on the rifle. Due to Newton's 3rd law, the reaction force on the rifle is equal and opposite to the action force on the bullet.
What is the magnitude of Earth's gravitational force on a 1-kg body at Earth's surface? A) 6.67 x 10-11 kg B) 6.67 x 10-11 N C) 10 N D) 1 kg
C) 10 N
What is the magnitude of the gravitational force between two 1-kg bodies that are 1m apart? A) 6.67 x 10-11 kg B) 1kg C) 6.67 x 10-11 N D) 10 N
C) 6.67 x 10-11 N
How does the force of gravity between two bodies change when the distance between them is doubled? A) The force doubles B) The force is cut in half C) The force decreases to 1/4 of its initial value D) The force quadruples
C) The force decreases to 1/4 of its initial value.
Why are occupants of the International Space Station weightless? A) They are so far from Earth that gravity is essentially zero B) Centripetal force cancels gravity in the space station C) They are in free fall D) The floor of the space station is made from favorite which blocks gravity.
C) They are in free fall
When G was first measured by Henry Cavendish, newspapers of the time hailed his experiment as the "weighing Earth experiment." Why? A) With a known mass and a scale, you can calculate the unknown mass of Earth B) By dropping a large lead sphere, you can measure the acceleration of Earth and find it's mass C) With a known mass, a scale, and the radius of Earth you can calculate the unknown mass of Earth if you know G D) With a known mass and the radius of the Earth, you can calculate the unknown mass of Earth.
C) With a known mass, a scale, and the radius of Earth, you can calculate the unknown mass of Earth if you know G
4) What color light is transmitted by a piece of blue glass? A) red B) white C) blue D) yellow E) orange
C) blue
16) How many colors of ink are used to print full-color pictures? A) one plus black B) two plus black C) three plus black D) four plus black E) six plus black
C) three plus black
Why are the magnetic fields of superconducting magnets often stronger than those of conventional magnets?
Conventional magnets based on iron have a maximum magnetization that occurs when all of the domains are aligned. This saturation magnetization is weaker than the magnetic field of superconducting coils.
What is the resulting color if equal intensities of red light and cyan light are combined?
Cyan + red = white cyan is made of blue + green, and (blue + green + red) = white. When each color is added to its opposite, white occurs.
How does the thickness of paint sprayed on a surface change when the sprayer is held twice as far away? A) It is the same thickness B) It is 1/2 as thick C) It is twice as thick D) It is 1/4 as thick
D) It is 1/4 as thick
Which has the higher tides: spring tides or neap tides? Why? A) Neap tides are higher, because the tides from the Moon and Sun add together B) Spring tides are higher, because the tides from the Moon and Sun partially cancel. C) Neap tides are higher because the tides from the Moon and Sun partially cancel. D) Spring tides are higher, because the tides from the Moon and Sun add together.
D) Spring tides are higher, because the tides from the Moon and Sun add together.
Why is black hole invisible? A) A black hole is made of matter that absorbs all wavelengths of light B) A black hole is surrounded by an opaque cloud of dust C) A black hole is black dwarf star D) The escape velocity of the black hole is greater than the speed of light.
D) The escape velocity of the black hole is greater than the speed of light.
The most harmful radiations are those that kill living cells. don't encounter cells. damage living cells.
Damage living cells
What two physics mistakes occur in a science fiction movie when you see and hear at the same time a distant explosion in outer space?
Distant sound should get to you after you see the light Sound cannot travel in a vacuum, so you shouldn't hear anything
What produces a magnetic field?
Electric charges in motion
Exactly what is it that enables an object to do work?
Energy enables an object to do work.
Which of these will penetrate into lead? alpha particle beta particle gamma ray. all of the above
Gamma ray
How does the heat emitted by lamps affect their efficiency?
Heat emitted reduces the efficiency.
How does the heat emitted by incandescent lamps affect their efficiency?
Heat emitted reduces the efficiency. CFLs emit less heat and more heat; a 25 W CFL = 100-W incandescent
if the resistance of a circuit remains constant while the voltage across the circuit decreases to half its former value, what change occurs in the current?
I=VR If voltage decreases to 1/2, current will also decrease to 1/2 I~V
The probability cloud for the electron in the hydrogen atom has an average radius quite different from the radius predicted by Bohr. in agreement with the orbital radius of Bohr. as yet not accurately measured.
In agreement with the orbital radius of Bohr
If the voltage impressed across a circuit is held constant while the resistance doubles, what change occurs in the current?
It is cut in half.
What effect does Earth's magnetic field have on the intensity of cosmic rays striking Earth's surface?
It reduces the intensity.
What is the unit of electrical resistance?
Ohm
Electric forces within an atomic nucleus tend to push it apart. hold it together. neither of these
Push it apart
Resultant of two vectors at right angles to each other
R = square root of x2 + y2 a2+b2=c2, square root of c2
What frequency ranges of the radiation curve do red, green, and blue light occupy?
Red: low, green: middle; blue: high frequencies
Hertz
The SI unit of frequency. One Hz = one vibration per seconds
Shock Wave
The cone-shaped disturbance created by an object moving at supersonic speed through a fluid
What exactly is an ampere?
The flow of one coulomb per second
hertz
The frequency of a wave is measured in _____. One of these is one cycle (vibration) per second.
Natural Frequency
The frequency that a sound wave vibrates in a specific object after a disturbance. This frequency is determined by the object's materials.
Why is iron magnetic and wood not?
The magnetic fields of individual iron atoms are strong enough to align the magnetic fields of neighbor atoms. The atoms in wood have much weaker magnetic fields.
What is meant by critical angle?
The minimum angle of incidence inside a medium where light is totally reflected
The photons having greatest energy are those of green light. ultraviolet. infrared. red light. blue light.
Ultraviolet
meters
Wavelength is measured in _____.
energy
Waves transfer _____.
How does wetness affect the resistance of your body?
Wet bodies have lower resistance.
Why does a rope climber pull downward on the rope to move upward?
When the climber pulls the rope downward, the rope simultaneously pulls the climber upward- the direction desired by the climber.
out of phase
When waves are _____, the crests of one wave overlap the troughs of another to produce regions of zero amplitude.
Why can you exert greater force on the pedals of a bicycle if you pull up on the handlebars?
When you pull up on the handlebars, the handlebars simultaneously pull down on you. This downward force is transmitted to the pedals.
You push a heavy car by hand. The car, in turn, pushes back with an opposite but equal force on you. Doesn't this mean that the forces cancel one another, making acceleration impossible? Why or why not?
When you push the car, you exert a force on the car. When the car simultaneously pushes back on you, that force is on you not the car. You don't cancel a force on the car with a force on you. For cancellation, the forces have to be equal and opposite and act on the same object.
Explain how a radio works.
When you're switching the stations on the radio, you're cut ally adjusting the natural frequency of the electrons to match one of the incoming signals.
Newton's third law of motion
Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first.
white light
combination of all the colors
potential difference
difference in potential (voltage) between the ends of a conductor
spectroscope
instrument to analyze light from elements
node(s)
stationary point(s) on a standing wave
Which is more likely to break - a hammock stretched tightly between a pair of trees or one that sags more when you sit on it?
the hammock that is stretched tightly
How do the loudest sounds we can tolerate compare with the faintest sounds?
the loudest sounds are a trillion times more intense
why are red and cyan called complemntary colors?
they have all 3 parts of white
To what color of light are our eyes most sensitive?
yellow-green
Consider a baseball player batting a ball. (a) Identify the action-reaction pairs when the ball is being hit and (b) while the ball is in flight.
(a) Action; bat hits ball. Reaction; ball hits bat. (b) While in flight there are two interactions, one with the Earth's gravity and the other with the air. Action: Earth pulls down on ball (weight). Reaction: ball pulls up on Earth. And, action: air pushes ball, and reaction: ball pushes air.
You hold an apple over your head. (a) Identify all the forces acting on the apple and their reaction forces. (b) When you drop the apple, identify all the forces acting on it as it falls and the corresponding reaction forces. Neglect air drag.
(a) Two force pairs act; Earth's pull on apple (action), and apple's pull on Earth (reaction), Hand pushes apple upward (action), and apple pushes hand downward (reaction). (b) With no air drag, one force pair acts; Earth's pull on apple, and apple's pull on Earth. If air drag counts, then air pushes upward on apple (action) and apple pushes downward on air (reaction).
A boxer punches a sheet of paper in midair and brings it from rest up to a speed of 25 m/s in 0.05 s. (a) What acceleration is imparted to the paper? (b) If the mass of the paper is 0.003 kg, what force does the boxer exert on it? (c) How much force does the paper exert on the boxer?
(a) a = m∆v/∆t = (25 m/s)/(0.05 s) = 500 m/s2. (b) F = ma = m∆v/∆t = (0.003 kg)(25 m/s)/(0.05 s) = 1.5 N, which also is about 1/3 pound. (c) By Newton's third law, the same amount, 1.5 N.
4. How does the charge of one electron compare with the charge of another electron? How does it compare with the charge of a proton?
- all electrons have the same charge and mass -the charge of an electron is equal but opposite to the charge of a proton
10. How does one coulomb of charge compare with the charge of a single electron?
-1 C is the charge associated with 6.25 billion billion electrons
10. When the speed of a moving car is doubled, how much more kinetic energy does it have?
-4 times the KE
9. When is the potential energy of something significant?
-PE is significant when it changes, does work, or transforms to energy of another form
18. Can a machine multiply input force? Input distance? Input energy? (If your three answers are the same, see help; the last question is extremely important.)
-a machine can multiply input force or input distance, but NEVER input energy.
6. What is a positive ion? A negative ion?
-a positive ion has a net positive charge-it has lost one or more electrons -a negative ion, an ion with one or more extra electrons, is negatively charged
12. In terms of net charge, how does an electrically polarized object differ from an electrically charged object?
-an electrically polarized object can have zero net charge, while a charged object cannot have zero net charge. Polarized: one side of atom is more positive, other side is more negative Charged: entire atom is either positive or negative charged.
9. Name one particle that has exactly one quantum unit of charge?
-an electron or proton has exactly one quantum unit of charge
19. If a machine multiplies force by a factor of 4, what other quantity is diminished, and by how much?
-as force is increased, distance is decreased by the same factor
11. How is Coulomb's law similar to Newton's law of gravitation? How is it different?
-both laws are inverse-square laws; Newton's law is attractive but Coulomb's law for electrical forces, unlike gravity, can be attractive or repulsive -Coulomb's law-product of 2 charges -Newton's law-product of 2 masses
4. Which requires more work: lifting a 50-kg sack a vertical distance of 2 m or lifting a 25-kg sack a vertical distance of 4 m?
-both require the same work because the force x distance is the same for each
1. When is energy most evident?
-energy is most evident when it is changing
16. What is the source of energy in sunshine?
-fusion power
15. An apple hanging from a limb has potential energy because of its height. If it falls, what becomes of this energy just before it hits the ground? When it hits the ground?
-immediately before the apple hits the ground its initial PE becomes KE -when it hits the ground the energy becomes thermal energy
13. What is an electric dipole?
-in an electric dipole, positive and negative charges are separated on opposite sides of an object; distribution of electric charge is not perfectly even.
7. A car is raised a certain distance in a service-station lift and therefore has potential energy relative to the floor. If it were raised twice as high, how much more potential energy would it have?
-it would have twice the PE because the distance is two times greater
14. What will be the kinetic energy of a pile driver ram that starts from rest and undergoes a 10-kJ decrease in potential energy?
-its gain in KE will equal its decrease in PE, 10 kJ.
3. Cite an example in which a force is exerted on an object without doing work on the object.
-no work is done in pushing on a stationary wall
how does an electrically polarized object differ from an electrically charged object
-polarized object has the molecules aligned (+-) -charged objects have gained or lost electrons
6. If both sacks in the preceding question are lifted their respective distances in the same time, how does the power required for each compare? How about for the case in which the lighter sack is moved its distance in half the time?
-power for each is the same because the same work is done in the same time. -twice the power is required to do the same work on the lighter sack in half the time.
3. Which part of the atom is positively charged and which part is negatively charged.
-protons-positively charged -electrons-negatively charged
17. What is recycled energy?
-recycled energy is the reemployment of energy that otherwise would be wasted
13. How does speed affect the friction between road and a skidding tire?
-speed has little or no effect on friction
11. Compared with a car moving at some original speed, how much work must the brakes of a car supply to stop a car that is moving twice as fast? How will the stopping distances compare?
-the brakes must supply four times as much work. There is 4 times the stopping distance (2squared=4)
8. Two cars are raised to the same elevation on service-station lifts. If one car is twice as massive as the other, compare their gains of potential energy.
-the car that is twice as massive has twice the PE
20. A force of 50 N is applied to the end of a lever, which is moved a certain distance. If the other end of the lever moves one-third as far, how much force can it exert?
-the end moving 1/3 as far can exert 3 times the input force, 150 N.
2. Why does the gravitational force between Earth and the Moon predominate over electrical forces?
-there is no electrical force between Earth and the Moon. The much weaker gravitational force only attracts
14. Give an example of a common electric dipole?
-water molecules
8. What is meant by saying that charge is quantized?
-whole number multiples of the basic charge
5. What is most commonly the net charge of an atom?
-zero (an atom has as many electrons as protons)
12. If you push a crate horizontally with 100 N across a 10-m factory floor and the friction between the crate and the the floor is a steady 70 N, how much kinetic energy does the crate gain?
-ΔKE = work done = (100 N - 70 N)(10 m) = (30 N)(10 m) = 300 Nm = 300 J.
Does more current flow out of a battery than into it? Does more current flow into a lightbulb than out of it? Explain.
...
Your friend says that, when a compass is taken across the equator, it turns around and points in the opposite direction. Your other friend says that this is not true, that people in the Southern Hemisphere use the south magnetic pole of the compass to point toward the nearest pole. You're on; what do you say?
...
What is the fundamental source of electromagnetic radiation?
...vibrating electric charges, which emit vibrating electric and magnetic fields
How many decibels correspond to the lowest-intensity sound we can hear?
0 decibels
What is the acceleration of a car that maintains a constant velocity of 100 km/h for 10 s?
0 km/h·s
In a circuit of two lamps in series, where the current through one lamp is 1 A, what is the current through the other lamp? Defend your answe
1 amp. The same current flows through lamps in series.
In a circuit of two lamps in series, where the current through one lamp is 1 A, what is the current through the other lamp? Defend your answer.
1 amp. The same current flows through lamps in series. *the voltage will be split evenly among the lamps, though
C
1) Electrons are made to flow in a wire when there is A) an imbalance of charges in the wire. B) more potential energy at one end of the wire than the other. C) a potential difference across its ends.
What did Newton discover about gravity?
1) The equation for the force of gravity 2) The law of universal gravitation 3) The Newtonian synthesis
D
1) The source of all magnetism is A) tiny pieces of iron. B) tiny domains of aligned atoms. C) ferromagnetic materials. D) moving electric charge. E) none of these.
C
1) Which force binds atoms together to form molecules? A) gravitational B) nuclear C) electrical D) centripetal E) none of these
How does the intensity of a 30 dB sound compare with the intensity of a sound at the threshold of hearing?
1,000 times more intense
how much energy is given to each coulomb of charge that flows through a 1.5-V battery
1.5 V battery gives each coulomb of electrons 1.5 J of energy
What is the magnitude of Earth's gravitational force on a 1-kg body at Earth's surface?
10 kg
What is the acceleration of a car moving along a straight road that increases its speed from 0 to 100 km/h in 10 s?
10 km/h·s
Given the measurements 10 m, 10 m/s, and 10 m/s2, which is a measure of speed, which is a measure of distance, and which is a measure of acceleration?
10 m is distance, 10 m/s is speed, and 10 m/s2 is acceleration.
B
10) In an ac circuit, the electric field A) increases via the inverse square law. B) changes magnitude and direction with time. C) is everywhere the same. D) is non-existent. E) none of these.
C
10) Surrounding every moving electron is A) a magnetic field. B) an electric field. C) both of these. D) none of these.
A
10) The electrical force between charges is strongest when the charges are A) close together. B) far apart. C) the electric force is constant everywhere.
Calculate the resultant of the pair of velocities 100 km/h north and 75 km/h south. Calculate the resultant if both of the velocities are directed north.
100 km/h - 75 km/h = 25 km/h North 100 km/h + 75 km/h = 175 km/h North
C
11) Magnetism is due to the motion of electrons as they A) move around the nucleus. B) spin on their axes. C) both of these. D) none of these.
C
11) The current through a 10-ohm resistor connected to a 120-V power supply is A) 1 A. B) 10 A. C) 12 A. D) 120 A. E) none of these
C
11) The electrical force between charges depends on the A) magnitude of electric charges. B) separation distance between electric charges. C) both of these. D) none of these.
How much energy is supplied to each coulomb of charge that flows through a 12-V battery?
12 joules
How much energy is supplied to each coulomb of charge that flows through a 12-V battery?
12 joules ex. common automobile battery provides 12V electrical pressure to circuit. 12 J energy are supplied to each coulomb of charge made to flow in the circuit.
E
12) A 10-ohm resistor has a 5-A current in it. What is the voltage across the resistor? A) 5 V B) 10 V C) 15 V D) 20 V E) more than 20 V
C
12) A transistor is an example of A) a resistor. B) a superconductor. C) a semiconductor. D) a dry cell. E) electrostatic shielding
A
12) Magnetic domains normally occur in A) iron. B) copper. C) silver. D) all of these. E) none of these.
B
13) Magnetic field lines about a current-carrying wire A) extend radially from the wire. B) circle the wire in closed loops. C) both of these. D) neither of these.
C
13) Superconductors are noted for their A) high electric resistance. B) low electric resistance. C) absence of electric resistance.
B
13) When a 10-V battery is connected to a resistor, the current in the resistor is 2 A. What is the resistor's value? A) 2 ohms B) 5 ohms C) 10 ohms D) 20 ohms E) more than 20 ohms
A
14) Rub electrons from your hair with a comb and the comb becomes A) negatively charged. B) positively charge.
C
14) The force on an electron moving in a magnetic field will be the largest when its direction is A) the same as the magnetic field direction. B) exactly opposite to the magnetic field direction. C) perpendicular to the magnetic field direction. D) at an angle other than 90 degrees to the magnetic field direction. E) none of these.
What is the speed over the ground of an airplane flying at 100 km/h relative to the air caught in a 100-km/h right-angle crosswind?
141 km/h
A
15) An electron and a proton A) attract each other. B) repel each other.
A
15) The intensity of cosmic rays bombarding the Earth's surface is largest at the A) poles. B) mid-latitudes. C) equator.
C
15) The source of electrons lighting an incandescent ac light bulb is A) the power company. B) electrical outlet. C) atoms in the light bulb filament. D) the wire leading to the lamp. E) the source voltage.
A
16) A woman experiences an electrical shock. The electrons making the shock come from the A) woman's body. B) ground. C) power plant. D) hairdryer. E) electric field in the air.
B
16) If we think of the Earth as a magnet, its north (-seeking) pole is nearest A) the Hudson Bay region of Canada. B) Australia. C) both of these.
B
16) Two protons attract each other gravitationally and repel each other electrically. By far the greater is A) the gravitational attraction. B) the electrical repulsion. C) neither - they are the same.
B
17) The primary purpose of a lightning rod is to A) attract lightning and guide it to the ground. B) discharge the structure to which it is attached. C) cancel the electric field within the structure to which it is attached. D) induce within the structure to which it is attached a charge opposite to that of charged clouds overhead.
A
17) Which pole of a compass needle points to a south pole of a magnet? A) north pole B) south pole C) both of these
C
18) Pigeons navigate primarily by A) a good memory. B) a keen sense of smell. C) magnetic sensors in their heads. D) ultra-high-pitched sounds. E) none of these.
B
18) To say that an object is electrically polarized is to say A) it is electrically charged. B) its charges have been rearranged. C) its internal electric field is zero. D) it is only partially conducting. E) it is to some degree magnetic.
D
18) When a light switch is turned on in a dc circuit, the average speed of electrons in the lamp is A) the speed of sound waves in metal. B) the speed of light. C) 1000 cm/s. D) less than 1 cm/s. E) dependent on how quickly each electron bumps into the next electron.
B
19) Magnet A has twice the magnetic field strength of Magnet B and at a certain distance pulls on magnet B with a force of 100 N. The amount of force that magnet A exerts on magnet B is A) at or about 50 N. B) exactly 100 N. C) more information is needed.
A certain radioactive isotope placed near a Geiger counter registers 160 counts per minute. Eight hours later, the counter registers 10 counts per minute. What is the half-life of the isotope? 2 hours 4 hours 6 hours 8 hours none of the above
2 hours
B
2) An ampere is a unit of electrical A) pressure. B) current. C) resistance. D) all of these. E) none of these.
E
2) Magnetic compasses apparently were first used by A) Columbus. B) Greeks. C) Australian aborigines. D) Vikings. E) pigeons, then Chinese.
D
2) The fundamental force underlying all chemical reactions is A) gravitational. B) nuclear. C) centripetal. D) electrical. E) none of these.
B
20) Compared to the huge force that attracts an iron tack to a strong magnet, the force that the tack exerts on the magnet is A) relatively small. B) equally huge. C) more information is needed.
E
20) The electric power of a lamp that carries 2 A at 120 V is A) 1/6 watts. B) 2 watts. C) 60 watts. D) 20 watts. E) 240 watts.
D
20) When a car is struck by lightning, the resulting electric field inside the car is A) normally huge, but for a brief time. B) normally huge for a time longer than the lightning stroke itself. C) small enough to be safe for an occupant inside. D) zero.
sound waves with frequencies higher than ..
20,000hz are ultrasonic
What is the average frequency range of a young person's hearing
20-20,000 Hz
sound wave with frequencies below ..
20HZ are infrasonic
D
21) An electron is shot from the right, toward a spot just between the ends of the magnet. The electron A) is unaffected by the field. B) is attracted to one of the poles, and repelled from the other. C) is repelled by both poles, and therefore is turned back. D) is deflected into the plane of the page. E) accelerates straight toward the spot.
C
21) Electric potential, measured in volts, is the ratio of electric energy to amount of electric A) current. B) resistance. C) charge. D) voltage. E) none of these.
B
21) When two lamps are connected in parallel to a battery, the electrical resistance that the battery senses is A) more than the resistance of either lamp. B) less than the resistance of either lamp. C) none of these.
A
22) When two lamps are connected in series to a battery, the electrical resistance that the battery senses is A) more than the resistance of either lamp. B) less than the resistance of either lamp. C) none of these.
D
23) A possible cause for the existence of the Earth's magnetic field is A) moving charges in the liquid part of the Earth's core. B) great numbers of very slow moving charges in the Earth. C) convection currents in the liquid part of the Earth's core. D) all of these. E) none of these.
B
23) An uncharged pith ball is suspended by a nylon fiber. When a negatively charged rubber rod is brought nearby, without touching it, the pith ball A) becomes charged by induction. B) becomes polarized. C) is repelled by the rod. D) all of these. E) none of these.
C
23) On some early automobiles both headlights went out when one bulb burned out. The headlights must have been connected in A) parallel. B) perpendicular. C) series. D) haste.
A
24) Outside a magnet, magnetic field lines are conventionally drawn from A) north to south. B) south to north. C) either way.
E
24) The net charge on a charged capacitor A) depends on the area of the capacitor plates. B) depends on the distance between the capacitor plates. C) depends on the medium between the capacitor plates. D) all of these. E) none of these - the net charge is zero.
A
25) Charges on the plates of a charged capacitor reside on the surfaces A) between the capacitor plates. B) exterior to the capacitor.
B
25) There are electrons in the filament of the ac lamp in your bedroom. When you turn on the lamp and it glows, the glowing comes from A) different electrons; the ones that flow in the circuit to your lamp. B) the same electrons. C) the positive charges that flow in the filament.
A
25) Which force field can increase a moving electron's speed? A) electric field B) magnetic field C) both of these D) none of these
A
26) A 100-Watt lamp glows brighter than a 25-Watt lamp. The electrical resistance of the 100-Watt lamp must be A) less. B) greater. C) the same.
A
26) When the distance between two charges is halved, the electrical force between the charges A) quadruples. B) doubles. C) halves. D) is reduced by 1/4. E) none of these.
B
26) Which force field can accelerate an electron, but never change its speed? A) electric field B) magnetic field C) both of these D) none of these
A
27) In an electric circuit, the safety fuse is connected to the circuit in A) series. B) parallel.
C
27) Particle A and Particle B interact with each other. Particle A has twice the charge of particle B. Compared to the force on Particle A, the force on Particle B is A) four times as much. B) two times as much. C) the same. D) half as much. E) none of these.
C
27) When a bar magnet is broken in two as shown, each piece is A) as magnetic as the original magnet. B) actually stronger than the original magnet. C) at most half as strong as the original magnet. D) no longer magnetic.
B
28) If you comb your hair and the comb becomes positively charged, then your hair becomes A) positively charged. B) negatively charged. C) uncharged.
A
28) Superconducting electromagnets A) exist now. B) may be possible in the near future. C) may be possible in the distant future. D) are science fiction.
D
28) When a pair of 1-ohm resistors are connected in series, their combined resistance is A) 1 ohm, and when connected in parallel, 2 ohms. B) 2 ohms, and when in parallel, 1 ohm. C) 1/2 ohm, and when in parallel, 2 ohms. D) 2 ohms, and when in parallel, 1/2 ohm. E) none of these.
B
29) A circuit breaker serves the same purpose as A) a switch. B) a fuse. C) a capacitor. D) a battery. E) none of these.
D
29) To say that electric charge is conserved means that no case has ever been found where A) the total charge on an object has changed. B) the net amount of negative charge on an object is unbalanced by a positive charge on another object. C) the total amount of charge on an object has increased. D) net charge has been created or destroyed. E) none of these.
B
3) A wire that carries an electric current A) is electrically charged. B) may be electrically charged. C) is never electrically charged.
A
3) In an electrically neutral atom the number of protons in the nucleus is equal to the number of A) electrons that surround the nucleus. B) neutrons in the nucleus. C) both of these. D) neither of these.
C
3) Moving electric charges will interact with A) an electric field. B) a magnetic field. C) both of these. D) none of these.
What is the average speed in kilometers per hour of a horse that gallops a distance of 15 km in a time of 30 min?
30 km/hr
C
30) A capacitor is useful in A) boosting the energy output of a circuit. B) increasing the current in a resistor. C) smoothing pulsed current. D) switching dc to ac in a circuit. E) increasing or decreasing voltage.
B
30) A difference between electric forces and gravitational forces is that electrical forces include A) separation distance. B) repulsive interactions. C) the inverse square law. D) infinite range. E) none of these.
What is the wavelength of a wave that has a frequency of 1 Hz and travels at 300,000 km/s?
300,000 km 300,000 km/s X 1Hz(oscillation per second) = 300,000 km pg. 490
E
31) A conductor differs from an insulator in that a conductor A) has more electrons than protons. B) has more protons than electrons. C) has more energy than an insulator. D) has faster moving molecules. E) none of these.
C
32) In the 110-volt circuit shown, A) 110 coulombs of charge flow through the lamp every second. B) 110 joules of energy are converted to heat and light in the circuit every second. C) 110 joules of energy are given up by each coulomb of charge making up the current in the circuit. D) 110 joules of energy are shared among all the coulombs in the circuit at any instant. E) none of the above.
C
33) In the circuit of Figure 23-A, energy is given to the moving charges by A) the bulb. B) the wires. C) a generator which is not shown. D) none of these.
C
34) A capacitor is used to store A) charge. B) energy. C) both. D) neither.
D
34) The direction of an electric field is the direction of the force that it would exert on A) a neutron. B) an electron. C) an atom. D) a proton. E) a molecule.
E
35) The electric field around an isolated electron has a certain strength 1 cm from the electron. The electric field strength 2 cm from the electron is A) half as much. B) the same. C) twice as much. D) four times as much. E) none of these.
A
35) The number of electrons delivered daily to an average American home by an average power utility in the mid 1980s was A) zero. B) 110. C) 220. D) billions of billions. E) none of these.
B
36) If you use 10 J of work to push a coulomb of charge into an electric field, its voltage with respect to its starting position is A) less than 10 V. B) 10 V. C) more then 10 V.
C
36) Two lamps, one with a thick filament and one with a thin filament, are connected in series. The current is greater in the lamp with the A) thick filament. B) thin filament. C) the same in each lamp.
B
37) If you use 10 J of work to push a charge into an electric field and then release the charge, as it flies past its starting position, its kinetic energy is A) less than 10 J. B) 10 J. C) more than 10 J.
C
37) Two lamps, one with a thick filament and one with a thin filament, are connected in parallel to a battery. The voltage is greatest across the lamp with the A) thick filament. B) thin filament. C) both voltages are the same.
A
38) An electroscope is charged positively as shown by foil leaves that stand apart. As a negative charge is brought close to the electroscope, the leaves A) fall closer together. B) spread apart further. C) do not move.
A
38) Two lamps, one with a thick filament and one with a thin filament of the same material, are connected in parallel to a battery. The current is larger in the lamp with the A) thick filament. B) thin filament. C) current is the same in both.
C
39) Charge carriers in a metal are electrons rather than protons because electrons are A) negative. B) smaller. C) loosely bound. D) all of these. E) none of these.
B
39) Two lamps, one with a thick filament and one with a thin filament of the same material, are connected in series to a battery. The voltage is greater across the lamp with the A) thick filament. B) thin filament. C) voltage is the same for both.
C
4) If a steady magnetic field exerts a force on a moving charge, that force is directed A) opposite the motion. B) in the direction of the motion. C) at right angles to the direction of the motion.
B
41) A charged balloon neatly illustrates that something can have a great amount of A) potential energy and a low voltage. B) voltage and a small potential energy. C) both voltage and potential energy. D) none of these.
A
41) As more lamps are put into a parallel circuit, the overall current in the power source A) increases. B) decreases. C) stays the same.
D
42) A circuit is powered with a battery. Charge flows A) out of the battery and into the circuit. B) from the negative battery terminal to the positive terminal. C) after a couple seconds passes. D) through both the battery and the rest of the circuit. E) none of these.
C
42) Normally a balloon charged to several thousand volts has a relatively small amount of A) charge. B) energy. C) both. D) neither.
C
46) Two charges separated by one meter exert 1-N forces on each other. If the magnitude of each charge is doubled, the force on each charge is A) 1 N. B) 2 N. C) 4 N. D) 8 N. E) none of these.
B
47) The electrical force on a 2-C charge is 60 N. What is the value of the electric field at the place where the charge is located? A) 20 N/C B) 30 N/C C) 60 N/C D) 120 N/C E) 240 N/C
D
47) What is the power rating of a light bulb if 0.8 A flow through it when it is connected to a 120-volt outlet? A) 12 W B) 15 W C) 60 W D) 96 W E) 120 W
B
48) The headlights, radio, and defroster fan in an automobile are connected in A) series. B) parallel.
C
48) Two charged particles repel each other with a force F. If the charge of one of the particles is doubled and the distance between them is also doubled, then the force will be A) F. B) 2 F. C) F/2. D) F/4. E) none of these.
A
49) A 4-ohm resistor is connected in parallel with a 6-ohm resistor. This combination produces an equivalent resistance of A) 2.4 ohms. B) 4 ohms. C) 5 ohms. D) 5.5 ohms. E) 10 ohms.
A
49) Two charged particles attract each other with a force F. If the charges of both particles are doubled, and the distance between them also doubled, then the force of attraction will be A) F. B) 2 F. C) F/2. D) F/4. E) none of these.
C
5) If a steady magnetic field exerts a force on a moving charge, that force is directed A) in the direction of the field. B) opposite the direction of the field. C) at right angles to the direction of the field.
A
5) Strip electrons from an atom and the atom becomes a A) positive ion. B) negative ion. C) different element.
A
5) Which statement is correct? A) Charge flows in a circuit. B) Voltage flows through a circuit. C) Resistance is established across a circuit. D) Current causes voltage.
C
50) The power dissipated in a 4-ohm resistor carrying 3 A is A) 7 W. B) 18 W. C) 36 W. D) 48 W. E) not enough information to say.
E
50) When a single charge q is placed on one corner of a square, the electric field at the center of the square is F/q. If three other equal charges are placed on the other corners, the electric field at the center of the square due to these four equal charges is A) F/q. B) 4F/q. C) F/(2q). D) F/(4q). E) none of these.
A
51) When a single charge q is placed at one corner of a square, the electric field at the center of the square is F/q. If two other equal charges are placed at the adjacent corners of the square, the electric field at the center of the square due to these three equal charges is A) F/q. B) 4F/q. C) F/(2q). D) F/(4q). E) none of these.
A
51) Which is more dangerous, touching a faulty 110-volt light fixture, or a Van de Graaff generator charged to 100,000 volts? A) touching the light fixture B) touching the generator C) Touching both are about equally dangerous.
A
52) A 60-W light bulb and a 100-W light bulb are each rated at 120 V. Which light bulb has a larger resistance? A) the 60-W bulb B) the 100-W bulb C) Both have the same resistance.
C
52) An electron is pushed into an electric field where it acquires a 1-V electrical potential. If two electrons are pushed the same distance into the same electric field, the electrical potential of the two electrons is A) 0.25 V. B) 0.5 V. C) 1 V. D) 2 V. E) 4 V.
B
53) A 60-W light bulb and a 100-W light bulb are each connected to a 120 V outlet. Which light bulb has more current in it? A) the 60-W bulb B) the 100-W bulb C) Both have the same current.
B
53) The electric field inside an uncharged metal ball is zero. If the ball is negatively charged, the electric field inside the ball is then A) less than zero. B) zero. C) greater than zero.
B
54) Compared to the filament thickness of a 60-W light bulb, the filament of a 100-W light bulb will be A) thinner. B) thicker. C) the same.
B
54) Two charged particles held close to each other are released. As they move, the force on each particle increases. Therefore, the particles have A) the same sign. B) opposite signs. C) not enough information given.
B
55) Compared to a single lamp connected to a battery, two identical lamps connected in series to the same battery will carry A) more current. B) less current. C) the same current.
C
55) Two charged particles held close to each other are released. As the particles move, the velocity of each increases. Therefore, their charges have A) the same sign. B) opposite signs. C) not enough information given.
A
56) A positive charge and a negative charge held near each other are released. As they move, the force on each particle A) increases. B) decreases. C) stays the same.
A
56) Compared to a single lamp connected to a battery, two lamps connected in parallel to the same battery will carry A) more current. B) less current. C) the same current.
D
57) An electric heater is rated at 300 W when used in a 110-V circuit. The safety fuse in the circuit can handle 15 A of current. How many heaters can be safely operated in the circuit? A) 2 B) 3 C) 4 D) 5 E) more than 5
A
57) Two charged particles held near each other are released. As they move, the acceleration of each decreases. Therefore, the particles have A) the same sign. B) opposite signs. C) not enough information given.
C
58) A heater uses 20 A when used in a 110-V line. If electric power costs 10 cents per kilowatt hour, the cost of running the heater for 10 hours is A) $0.22. B) $0.55. C) $2.20. D) $5.50. E) none of these.
A
58) A proton and an electron are placed in an electric field. Which undergoes the greater acceleration? A) electron B) proton C) both accelerate equally D) neither accelerates
C
59) The current through two identical light bulbs connected in series is 0.25 A. The voltage across both bulbs is 110 V. The resistance of a single light bulb is A) 22 ohms. B) 44 ohms. C) 220 ohms. D) 440 ohms. E) none of these.
A hypothetical atom has four distinct energy states. Assuming all transitions are possible, the number of spectral lines this atom can produce is 7. 6. 5. more than 8. 8.
6
What is the net force that acts on a 10-N falling object when it encounter a 4 N of air resistance? 10 N of air resistance?
6 N and then 0 N.
In a circuit of two lamps in parallel, where there is a voltage of 6 V across one lamp, what is the voltage across the other lamp?
6 volts
In a circuit of two lamps in parallel, where there is a voltage of 6 V across one lamp, what is the voltage across the other lamp?
6 volts in series connections, the voltage drop is proportional to its resistance. Ohm's law applies separately to each device.
C
6) An iron rod becomes magnetic when A) positive ions accumulate at one end and negative ions at the other end. B) its atoms are aligned having plus charges on one side and negative charges on the other. C) the net spins of its electrons are in the same direction. D) its electrons stop moving and point in the same direction. E) none of these.
C
6) Electrons move in an electrical circuit A) by being bumped by other electrons. B) by colliding with molecules. C) by interacting with an established electric field. D) because the wires are so thin. E) none of these.
B
6) To say that electric charge is quantized is to say that the charge on an object A) may occur in an infinite variety of quantities. B) is a whole-number multiple of the charge of one electron. C) will interact with neighboring electric charges. D) can be neither created nor destroyed.
What is the magnitude of the gravitational force between two 1-kg bodies that are 1 m apart?
6.67 x 10^-11
D
60) A power line with a resistance of 2 ohms has a current of 80 A in it. The power dissipated in the line is A) 40 W. B) 160 W. C) 320 W. D) 12,800 W. E) none of these.
If the fundamental frequency of a note is 200 Hz, what is the frequency of the third harmonic?
600 Hz
E
61) What is the resistance of a 120-W incandescent lamp connected to a 120-V power supply? A) 1 ohm B) 60 ohms C) 100 ohms D) 144 ohms E) none of these
D
62) Compared to the amount of electric current in the filament of a lamp, the amount of current in the connecting wire is A) definitely less. B) often less. C) actually more. D) the same. E) incredibly, all of these.
B
63) Connect a pair of lamps in series and you draw current from the connected battery. Connect the same lamps in parallel and you draw A) the same current. B) more current. C) less current. D) ...sometimes more, sometimes less.
C
7) Heat a copper wire and its electric resistance A) decreases. B) remains unchanged. C) increases.
A
7) Like kinds of magnetic poles repel while unlike kinds of magnetic poles A) attract. B) repel also. C) may attract or repel.
D
7) To say that electric charge is conserved is to say that electric charge A) may occur in an infinite variety of quantities. B) is a whole number multiple of the charge of one electron. C) will interact with neighboring electric charges. D) can be neither created nor destroyed.
A nurse counts 76 hearbeats in one minute. What are the period and frequency of the heart's oscillations?
76 heartbeats/60 seconds = 1 heartbeat/ 0.79 seconds frequency = 1/period = 1/0.79 s = 1.27 The period is 0.79 seconds and the frequency is 1.27 Hz.
A
8) Several paper clips dangle from the north pole of a magnet. The induced pole in the bottom of the lowermost paper clip is a A) north pole. B) south pole. C) north or south pole - no difference really.
C
8) Stretch a copper wire so that it is thinner and the resistance between its ends A) decreases. B) remains unchanged. C) increases.
At what sound intensity does damage to human hearing begin?
85 dB
When radium (A = 88) emits an alpha particle, the resulting nucleus has atomic number 92. 88. 90. 86. none of the above
86
B
9) A main difference between gravitational and electric forces is that electrical forces A) attract. B) repel or attract. C) obey the inverse-square law. D) act over shorter distances. E) are weaker.
C
9) An iron nail is more strongly attracted to the A) north pole of a magnet. B) south pole of a magnet. C) north or south pole - no difference really.
What is the magnitude of the gravitational force between Earth and a 1-kilogram body?
9.8N
longitudinal wave
A _____ oscillates parallel to the direction of wave motion.
Does a battery produce dc or ac? Does the generator at a commercial power station produce dc or ac?
A battery produces direct current, which refers to the flowing of charges in one direction. A commercial power station produces alternating current, where electrons in circuit are moved first in one direction then opposite.
An element will decay to an element with higher atomic number in the periodic table if it emits a gamma ray. a proton. an alpha particle. a beta particle. none of the above
A beta particle
A diode converts ac to pulsed dc. What electrical device smoothes the pulsed dc to a smoother dc?
A capacitor
What does a changing *magnetic* field induce?
A changing *electric* field. "If lights were to slow down, its changing electric field would generate a weaker magnetic field, which, in turn, would generate a weaker electric field, and so on, until the wave died out."
What does a changing *electric* field induce?
A changing *magnetic* field. "If light were to speed up, the changing electric field would generate a stronger magnetic field, which in turn would generate a stronger electric field, etc."
Which warms more quickly in sunlight - a colorless or a colored piece of glass?
A colored piece of glass warms quickest because it absorbs more frequencies of light, thus converting the energy to temperature.
What condition is necessary for the sustained flow of water in a pipe? What analogous condition is necessary for the sustained flow of charge in a wire?
A continuous pressure difference, often provided by a pump, is needed for water to flow. A continuous potential difference, often provided by a battery, is needed for charge to flow.
What condition is necessary for the sustained flow of water in a pipe? What analogous condition is necessary for the sustained flow of charge in a wire?
A continuous pressure difference, often provided by a pump, is needed for water to flow. A continuous potential difference, often provided by a battery, is needed for charge to flow. Once a common potential is reached, or difference ceases, flow ceases. *Charge flow is actually *particle* flow. Negative charge flow= electrons, negative ions. Positive flow = protons or positive ions are flowing.
What condition is necessary for the flow of heat? What analogous condition is necessary for the flow of charge?
A difference in temperature is needed for heat to flow. A difference in electrical potential is needed for charge to flow.
What condition is necessary for the flow of heat? What analogous condition is necessary for the flow of charge?
A difference in temperature is needed for heat to flow. A difference in electrical potential is needed for charge to flow. The flow of charge persists as long as there is *potential difference* ; without a potential difference, or once both ends reach an equilibrium, flow ceases.
In the simplest sense, a force is a push or a pull. In a deeper sense, what is a force?
A force is an interaction between one thing and another.
What is a radiation curve?
A graphical distribution of brightness versus frequency, of sunlight. Most whites produced from reflected sunlight share this frequency distribution
What is a gravitational field, and how can its presence be detected?
A gravitational field is the influence that a massive body extends into the space around itself, producing a force on another massive body. If you are in the presence of a gravitational field, the gravitational force will pull you towards the object along its gravitational field lines.
Why does a high-flying airplane cast little or no shadow on the ground below while a low-flying airplane casts a sharp shadow?
A high flying airplane is farther away from a surface (ground), thus the shadow is less distinct or nonevident as the penumbra expands into a big blur. A low flying airplane casts a sharp shadow since it is near the ground surface, with light coming from slightly different directions not spreading out much below it. (a larger umbra)
How does pitch relate to frequency?
A high-pitched sound has a high vibration frequency, while a low-pitched sound has a low vibration frequency.
How does the avalanche of photons in a laser beam differ from the hordes of photons emitted by an incandescent lamp?
A laser beam propagates in one direction, with one wavelength that is all in phase (coherent, retains intensity). Light from an incandescent lamp does none of these (incoherent, spreads, loses intensity with distance).
longer period; lower frequency
A long pendulum has a _____ and a _____ than a shorter pendulum.
Temperature
A measure of how hot (or cold) something is; specifically, a measure of the average kinetic energy of the particles in an object.
What is a metastable state?
A metastable state is a long-lived excited state. "A prolonged state of excitation. Can be several hours. If the source of excitation is removed, an afterglow remains while millions of atoms spontaneously undergo gradual de-excitation. Older clock dials containing radium or other radioactive material continuously supplying energy glow indefinitely in the dark." Bioluminescence of creatures!
1.33 Hertz
A nurse counts 80 heartbeats in one minute (60 seconds). What is the frequency of the heart's beats?
What kind of lens can be used to produce a real image? A virtual image?
A real image can only be made with a converging lens. A virtual image can be made with either a converging or diverging lens.
What is the angle between a light ray and its wavefront?
A right angle
diode
A semiconductor that permits current to flow through it in only one direction.
Complex Sound
A sound that is combined into a superposition from other sound waves at other frequencies and amplitudes.
Echo
A sound wave that is reflected or bounces off of a boundary.
Standing Wave
A stationary interference pattern formed in a medium when two sets of identical waves pass through the medium in opposite directions
Cite three examples of a vector quantity and three examples of a scalar quantity.
A vector is a quantity that specifies both a magnitude and a direction. Examples: displacement, velocity, acceleration, force and electric field A scalar is a quantity that is completely specified by its magnitude and has no direction. Examples: mass, volume, distance, energy, and time
Does a viewer see a single color or a spectrum of colors coming from a single faraway drop?
A viewer sees a single color from a single faraway drop.
Distinguish between a virtual image and a real image. Mention in each case whether the image made by a single lens is right-side up or inverted.
A virtual image, unlike a real image, cannot be displayed on a screen. A virtual image is upright, whereas a real image is inverted.
Between a watt, a kilowatt, and a kilowatt-hour, which is a unit of power and which is a unit of energy?
A watt is power, a kilowatt is power, and a kilowatt-hour is energy.
Between a watt, a kilowatt, and a kilowatt-hour, which is a unit of power and which is a unit of energy?
A watt is power, a kilowatt is power, and a kilowatt-hour is energy. *power = energy/unit time* *energy = power X time*
42 m/s
A wave has a frequency of 14 Hz and a wavelength of 3 meters. At what speed will this wave travel?
0.63 m
A wave has a frequency of 540 Hz and is traveling at 340 m/s. What is its wavelength?
0.16 Hz
A wave has a wavelength of 125 meters and is moving at a speed of 20 m/s. What is it's frequency?
Longitudinal Waves
A wave in which the medium vibrates parallel to (along) the direction in which the wave travels. Sound waves are longitudinal.
Transverse Wave
A wave in which the medium vibrates perpendicularly (at right angles) to the direction in which the wave travels. Light waves and waves on string instruments are transverse.
Would the spring inside a bathroom scale be more compressed or less compressed if you weighed yourself in an elevator that was moving upward at constant velocity? Downward at constant velocity? A)There would be no more compression and no more expansion for both upward and downward motion B) More compressed while moving upward and less compressed while moving downward C) More compressed while moving upward and while moving downward D) Less compressed while moving upward and more compressed while moving downward.
A) There would be no more compression and no more expansion for both upward and downward motion.
Do tides occur in the molten interior of Earth for the same reason that tides occur in the oceans? A) Yes due to the difference in gravitational force across the core B) Yes, due to the strength of the gravitational force at the center of the core. C) No, due to the difference in gravitational force across the core. D) No, due to the strength of the gravitational force at the center of its core.
A) Yes due to the difference in gravitational force across the core
7) Which will warm up quicker in sunlight? A) a piece of colored glass B) a piece of clear glass C) both the same
A) a piece of colored glass
2) When the frequency of light matches the natural frequency of molecules in a material, light is A) absorbed. B) transmitted. C) reflected. D) none of these
A) absorbed.
14) Colors seen on TV results from color A) addition. B) subtraction. C) either of these D) neither of these
A) addition.
10) If three primary colors of light are to shine on a white wall to produce a white spot, the primaries must be A) additive. B) subtractive. C) multiplicative. D) divisive.
A) additive.
The newton is a unit of A) force. B) inertia. C) density. D) mass.
A) force.
For a planet of uniform density, how would the magnitude of the gravitational field halfway to the center compare with the field at the surface? A) g/2 m/s^2 B) Zero m/s^2 C) g m/s^2 D) g/2N
A) g/2 m/s^2
A cannon fires a cannonball. While the cannonball is accelerating within the cannon, the magnitude of the acceleration of the cannonball is _________ that of the cannon. A) greater than B) equal to C) less than
A) greater than Although the forces are equal and opposite, the acceleration is greater since the cannonball's mass is much lower.
37) If sunlight were green instead of white, the most comfortable color to wear on a cold day would be A) magenta. B) yellow. C) green. D) blue. E) violet.
A) magenta.
30) The whiteness of clouds is evidence in the clouds for a variety of A) particle sizes. B) molecules. C) "seeds" upon which condensation of cloud material forms. D) light intensities. E) water prisms.
A) particle sizes.
41) If the atmosphere were about 40 times thicker, at noon the sun would appear A) red-orange. B) orange-green. C) green-blue. D) blue-violet. E) none of these
A) red-orange.
45) The redness of the lunar eclipse is evidence for the A) refraction of sunsets and sunrises all around the world. B) infrared light continually emitted by the moon. C) scattering of lower frequencies of light by the moon. D) faintly radiating atoms in our own atmosphere when sunlight is not incident upon them. E) dim light that is incident upon the moon by Jupiter and other planets.
A) refraction of sunsets and sunrises all around the world.
25) Sunsets are red, blue jays are blue; the reason's the same: A) scattered sunlight - nothing new. B) pigments that reflect in the blue. C) aerosols and all such goo. D) no one knows, but it is true.
A) scattered sunlight - nothing new.
A rock weighs 30 N on Earth. A second rock weighs 30 N on the moon. Which of the two rocks has the greater mass? A) the one on the moon B) the one on Earth C) They have the same mass.
A) the one on the moon
When are you most aware of your motion in a moving vehicle: when it is moving steadily in a straight line or when it is accelerating? If you were in a car that moved with absolutely constant velocity (no bumps at all), would you be aware of the motion?
Accelerating. You would not be aware of the motion if you did not look outside the car.
A new theory conforms to the correspondence principle when it updates the essence of the old theory. accounts for verified results of the old theory. corresponds to all theories in nature. connects two or more theories.
Accounts for verified results of the old theory
Why are red, green, and blue called the additive primary colors?
Adding appropriate amounts of red plus green plus blue lights can produce almost any color of the spectrum.
By adjusting a TV image with a remote you can affect only the image. participate with the action on the screen. both of these neither of these
Affect only the image
Your friend says that frequency is a quantitative measure of pitch. Do you agree or disagree.
Agree
Why is argon, instead of air, used inside an incandescent bulb?
Air contains oxygen that would react with and destroy the tungsten filament. Argon is an inert noble gas.
Why does the sky normally appear blue?
Air molecules have resonances in the ultraviolet, so they scatter blue light more than red light. These particles emit light most strongly in the UV region, so they have natural frequencies higher than that of visible light. This means that blue light will be closer in frequency that red light, scattered more strongly
transverse
All electromagnetic waves (all waves other than sound) are _____ waves.
In what way are magnetic poles very different from electric charges?
All magnets have both south and north poles. Electric charges can exist as singular entities.
A quark is a fundamental particle not composed of smaller parts. much smaller than a nucleon. that makes up a nucleon. all of the above none of the above
All of the above
Credit for research in our knowledge of the electron includes J.J. Thomson. William Crookes. Robert Millikan. all of the above none of the above
All of the above
The idea of complementarity is evident in the yin-yang symbol of Eastern cultures. dual nature of light. notion of opposites being components of a whole. all of the above none of the above
All of the above
When Millikan observed oil drops hovering at rest in his chamber, he knew that an upward electric force balanced the weight of each drop. the net force on each drop was zero. each drop was in mechanical equilibrium. all of the above none of the above
All of the above
When do cosmic rays penetrate your body?
All the time
When do cosmic rays penetrate your body?
All the time! In spite of Earth's protective magnetic field, "secondary" rays reach the surface when "primary" rays strike atomic nuclei high in atmosphere. The number increases with altitude.
Human damage is usually highest for radiation by alpha particles. beta particles. either of the above none of the above
Alpha particles
What is a galvanometer called when it has been calibrated to read current? When it has been calibrated to read voltage?
Ammeter (detects amperes) voltmeter (detects volts, electric potential)
What is a galvanometer called when it has been calibrated to read current? When it has been calibrated to read voltage?
Ammeter, voltmeter
How does a galvanometer detect electric current?
An electric current flows through a wire in a magnetic field. The deflection force on the wire acts against a spring. The compression of the spring is proportional to current.
How does a galvanometer detect electric current?
An electric current flows through a wire in a magnetic field. The deflection force on the wire acts against a spring. The compression of the spring is proportional to current. The coil is mounted for movement while the magnet is held stationary. Greater currents in windings = greater deflection.
Quantum uncertainties are most predominant for simultaneously measuring the speed and location of an electron. a spitball. a baseball. none of the above
An electron
Distinguish between analog and digital for how the sound signal is captured on phonograph records versus a CD?
Analog recordings on a record store a continuous trace of motion, whereas digital recordings on a CD record digital values sampled many times a second
Suppose that two carts, one twice as massive as the other, fly apart when the compressed spring that joins them is released. What is the acceleration of the heavier cart relative to that of the lighter cart as they start to move apart?
As in the preceding exercise, the force on each cart will be the same. But since the masses are different, the accelerations will differ. The twice-as-massive cart will undergo only half the acceleration of the less-massive cart.
Why re all tides greatest at the time of a full Moon or new Moon? A) At full moon and new moon, the tides from the moon and the sun add because they make a right angle with Earth. B) At full moon and new moon the tides from the Moon and the Sun add because they are in line with Earth. C) At full moon and new moon the tides from the Moon and the Sun partially cancel because they are in line with Earth. D) At full moon and new moon, the tides from the Moon and the Sun partially cancel because they make a right angle with Earth.
B) At full moon and new moon the tides from the Moon and the Sun add because they are in line with Earth.
A player catches a ball. Consider the action force to be the impact of the ball against the player's glove. The reaction to this force is the A) player's grip on the glove. B) force the glove exerts on the ball. C) muscular effort in the player's arms. D) friction of the ground against the player's shoes. E) none of these
B) force the glove exerts on the ball.
8) Light shines on a pane of green glass and a pane of clear glass. The temperature will be higher in the A) clear glass. B) green glass. C) Neither - it will be the same in each.
B) green glass.
19) A mixture of cyan and yellow pigments appears A) orange. B) green. C) magenta. D) blue. E) blackish brown.
B) green.
A person pushes a large crate across the room from left to the right. Friction acts on the crate as well as on the person's feet. If the person pushes with a force greater than the force of friction between the crate and floor, the net force on the crate A) is directed to the left. B) is directed to the right. C) is zero, since all forces cancel with their reaction pair partner.
B) is directed to the right. The net force on the crate is equal to the force exerted on it by the person minus the force of friction.
28) The sun is more likely to appear red at sunset than in the middle of the day as a result of the A) scattering of lower frequencies by larger particles in the air. B) longer path of air through which sunlight travels. C) lower frequencies of light emitted late in the day by the sun. D) pollutants emitted by humans in daylight hours. E) absorption effects of the smaller particles in the air.
B) longer path of air through which sunlight travels.
In which case would you have the largest mass of gold? If your chunk of gold weighed 1 N on the A) Earth. B) moon. C) planet Jupiter
B) moon.
9) The colored dots that make up the color on a TV screen are A) red, blue, yellow. B) red, blue, green. C) yellow, blue, green. D) magenta, cyan, yellow. E) red, green, yellow.
B) red, blue, green.
23) The sky is blue because air molecules in the sky act as tiny A) mirrors which reflect only blue light. B) resonators which scatter blue light. C) sources of white light. D) prisms. E) none of these
B) resonators which scatter blue light.
21) Which interacts more with sounds of relatively high frequencies? A) large bells B) small bells C) both the same
B) small bells
If Earth shrank, but there was no change in its mass, then what would happen to your weight at the surface? A) It would decrease B) It would increase C) It would stay the same D) It would decrease at first and then increase
B)It would increase
As seen from above, a stubborn stump is pulled by a pair of ropes, each with a force of200 N, but at different angles as shown. From greatest to least, rank the net force on the stump.
B, A, C
Here we see a top view of an airplane being blown off course by wind in three different directions. Rank the speeds of the airplane across the ground from fastest to slowest.
B, A, C
Which of the following are creatures that are known to harbor tiny magnets within their bodies?
Bacteria (single domain grains), pigeons (multiple domain in skulls), bees (abdomen), wasps, monarch butterflies, and sea turtles *magnetite crystals in human brain, too!
A magnetic field can deflect a beam of electrons, but it cannot do work on the electrons to change their speed. Why?
Because the magnetic field exerts a force that is perpendicular (at right angles) to the velocity of the electron. (fig. 24.13, pg. 460 in book) This force causes the electron to change direction a little, and so the velocity is now in a different direction. Since the force is always at right angles, this force constantly alters the direction and eventually the electrons travel in a circular path.
when a cannon is fired, why do the cannon ball and cannon have very different accelerations?
Because they differ in mass
According to Louis de Broglie, a material particle has particle properties. wave properties. both of these neither of these
Both of these
In which of these processes is an element transformed into a completely different element? alpha decay beta decay both of these none of the above
Both of these
Pure elements can be transformed into entirely different elements by radioactive decay. transmutation. both of these neither of these
Both of these
Spectral lines for an element are often in the ultraviolet region. infrared region. both of these neither of these
Both of these
The radioactive half-life of a material is the time for half of an original quantity of the material to decay. its decay rate to reduce to half. both of these neither of these
Both of these
What is conserved when a photon collides with an electron? energy momentum both of these neither of these
Both of these
In the Doppler effect, does frequency change? does wavelength change? does wave speed change?
Both the frequency and wavelength change. The wave speed remains constant.
If a proton and an electron have the same momentum, the longer wavelength belongs to the proton. electron. both the same
Both the same
Ken and Joanne are astronauts floating some distance apart in space. They are joined by a safety cord whose ends are tied around their waists. If Ken starts pulling on the cord, will he pull Joanne toward him, or will he pull himself toward Joanne, or will both astronauts move? Explain.
Both will move. Ken's pull on the rope is transmitted to Joanne, causing her to accelerate toward him. By Newton's third law, the rope pulls back on Ken, causing him to accelerate toward Joanne.
If you had two bars of iron - one magnetized and one unmagnetized - and no other materials at hand, how could you determine which bar was the magnet?
Break them each in half. If bar A's fragments are indifferent, then bar A is the virgin iron bar. If bar B's fragments are attracting and repelling depending upon configuration, just as two bar magnets usually would, then bar B is the originally magnetized bar.
A device that shows the bending of particle trails in liquid hydrogen is a spark chamber. streamer chamber. bubble chamber. all of the above none of the above
Bubble chamber
The rope is repositioned as shown and still supports the 50-N lantern. Is the tension in the rope less than, equal to, or more than 50 N? Use the parallelogram rule to defend your answer.
By the parallelogram rule, the tension is greater than 50 N.
In what sense does the Moon "fall"? A) The moon does not "fall" instead, it moves in a circle at a constant radius. B) The Moon "falls" away from Earth a bit on every orbit C) It falls away from the straight path that it would follow if there were no forces acting on it. D) The Moon "falls" toward Earth a bit on every orbit.
C) It falls away from the straight path that it would follow if there were no forces acting on it.
Would the springs inside a bathroom scale be more compressed or less compressed if you weighed yourself in an elevator that was accelerating upward? downward? A) Less compressed while accelerating upward, but more compressed while accelerating downward. B) Less compressed while accelerating upward and while accelerating downward. C) More compressed while accelerating upward, but less compressed while accelerating downward. D) More compressed while accelerating upward and while accelerating downward.
C) More compressed while accelerating upward, but less compressed while accelerating downward.
What was the cause of perturbations discovered in the orbit of the planet Uranus? What later discovery did this lead to? A) Pluto caused the perturbations, and later Einstein's theory of gravitation was discovered. B) Pluto caused the perturbations and later Neptune was discovered. C) Neptune caused the perturbations and later Pluto was discovered. D) Neptune caused the perturbations, and later Newton's law of Universal Gravitation was discovered.
C) Neptune caused the perturbations and later Pluto was discovered.
Describe how the gravitational forces from the Sun and the Moon compare from one of Earth to the other? A) The sun exerts a stronger force on the side of Earth furthest from the Sun, and the Moon exerts a stronger force on the side furthest from the Moon. B) The sun exerts a stronger force on the side of Earth furthest from the Sun, and the Moon exerts a stronger force on the side nearest the Moon. C) The sun exerts a stronger force on the side of Earth nearest the Sun, and the Moon exerts a stronger force on the side nearest the moon D) The sun exerts a stronger force on the side of Earth nearest the Sun, and the Moon exerts a stronger force on the side furthest from the Moon.
C) The sun exerts a stronger force on the side of Earth nearest the Sun, and the Moon exerts a stronger force on the side nearest the moon
A large man is playing a game of tug-o-war with a small child. The man causes the child to skid towards the man as the man is walking backwards. Which person is pulling on the rope harder? A) The child is pulling harder. B) The large man is pulling harder. C) The two are pulling equally hard on the rope.
C) The two are pulling equally hard on the rope. Even though the large man is stronger, he can't pull harder than the tension of the rope, which is the same as the tension on the other end of the rope. Due to Newton's 3rd law, the tension of the rope is equal to the strength either person is pulling on the rope, and so the each person is pulling just as hard as the other person.
An airplane flies north and travels with a speed of 100 miles per hour with respect to the air. If the wind blows towards the east with a speed of 100 miles per hour, in which direction is the airplane traveling with respect to the ground? A) To the east. B) To the north. C) To the northeast.
C) To the northeast. the final velocity is due to the addition of the velocity of the airplane with respect to the air and the wind velocity to the East.
Where do you weight more: At the bottom of Death Valley or atop one of the peaks of the Sierra Nevada? Why? A) You weight more in Death Valley, because more atmosphere pushes down on you B) You weigh more on the summit, because the higher you go, the harder you fall C) You weigh more in Death Valley because you are closer to the center of the Earth. D) You weigh more on the summit because the air buoys you up less.
C) You weigh more in Death Valley because you are closer to the center of the Earth.
Give an example of when your weight is greater than mg. Give an example of when your weight is 0. A) Your weight is greater than mg when you are accelerating downward. Your weight is zero when you are in free fall. B) Your weight is greater than mg when you are on top of a mountain. Your weight is 0 when you are in free fall. C) Your weight is greater than mg when you are accelerating upward. Your weight is zero when you are in free fall. D) Your weight is greater than mg when you are in free fall. Your weight is zero when you are accelerating upward.
C) Your weight is greater than mg when you are accelerating upward. Your weight is zero when you are in free fall.
Whenever the net force on an object is zero, its acceleration A) may be more than zero B) may be less than zero. C) is zero.
C) is zero.
26) The sky is the deepest blue A) just before a rainstorm. B) during a rainstorm. C) just after a rainstorm. D) when the air is humid. E) just before sunset.
C) just after a rainstorm.
An object's weight may properly be expressed in units of A) cubic centimeters. B) kilograms. C) newtons. D) meters.
C) newtons.
As a ball falls, the action force is the pull of Earth on the ball. The reaction force is the A) acceleration of the ball. B) none of these C) pull of the ball's mass on the Earth D) air resistance acting against the ball.
C) pull of the ball's mass on the Earth
5) The brightest color emitted by the sun is A) red. B) orange. C) yellow-green. D) green-blue. E) violet.
C) yellow-green.
12) The complementary color of blue is A) red. B) green. C) yellow. D) cyan. E) magenta.
C) yellow.
Both electrons and protons have equal-magnitude energy. charge. mass. all of the above none of the above
Charge
Does electric charge flow across a circuit or through a circuit? Does voltage flow across a circuit or is it impressed across a circuit?
Charge flows through and voltage is impressed across a circuit.
Does electric charge flow across a circuit or through a circuit? Does voltage flow across a circuit or is it impressed across a circuit?
Charge flows through and voltage is impressed across a circuit. *Water flows through and pressure changes across the the ends.
The finding that electrons occupy discrete orbits in an atom was first explained by the small mass of the electron. circumference of each orbit being an integral multiple of an electron wavelength. quantization of electric charge. none of the above
Circumference of each orbit being an integral multiple of an electron wavelength
What is a magnetic domain?
Clusters of atoms with their magnetic fields aligned
What is a magnetic domain?
Clusters of atoms with their magnetic fields aligned. Magnetic field is so strong that interactions among adjacent atoms cause large clusters to line up. Each domain is made up of billions of aligned atoms.
When Rutherford directed a stream of alpha particles at a gold foil, most particles spiraled. continued through. stopped. bounced back.
Continued through
When is your weight measured as mg? A) For a mass near the surface of Earth in free fall B) For a mass accelerating downward with an acceleration g C) For a mass accelerating upward with an acceleration g near the surface of the Earth. D) For a non-accelerating mass near the surface of the Earth.
D) For a non-accelerating mass near the surface of the Earth.
What happens to the strength of the gravitational field at the surface of a star that shrinks? A) it decreases B) It stays the same C) It first increases and then it decreases D) It increases
D) It increases
Would a torque on the Moon occur if the Moon were spherical, with both its center of mass and center of gravity in the same location? Why? A)No. The torque requires only a difference in force across the Moon B) Yes. The torque occurs even when the center of mass and the center of gravity are at the same location. C) Yes. the Torque requires a space between the center of mass and the center of gravity. D) No. the torque requires a distance between the center of Mass and the center of gravity.
D) No. the torque requires a distance between the center of Mass and the center of gravity.
What is the magnitude of the gravitational field at Earth's center? A) g N/kg B) 2g N/kg C) g/2 N/kg D) Zero N/kg
D) Zero N/kg
31) The greenish blue of water is evidence for the A) reflection of greenish-blue light. B) reflection of red light. C) absorption of greenish-blue light. D) absorption of red light. E) interaction between green and blue frequencies of light.
D) absorption of red light.
40) If molecules in the sky scattered orange light instead of blue light, sunsets would be colored A) orange. B) yellow. C) green. D) blue. E) none of these
D) blue.
34) A sheet of red paper will look black when illuminated with A) red light. B) yellow light. C) magenta light. D) cyan light. E) none of these
D) cyan light.
17) Different colors of light correspond to different light A) velocities. B) intensities. C) polarities. D) frequencies. E) none of these
D) frequencies.
20) Look at a full-color picture in a magazine with a magnifying glass and you'll see that the inks used are A) red, green, and blue. B) red, green, blue, and black. C) magenta, cyan, and yellow. D) magenta, cyan, yellow, and black. E) none of these
D) magenta, cyan, yellow, and black.
42) The atmosphere of Jupiter is more than 1000 km thick. From the planet's surface, the noon-day sun would appear A) white. B) faintly white. C) not at all. D) none of these
D) none of these
11) Complementary colors are two colors that A) look good together. B) are additive primary colors. C) are subtractive primary colors. D) produce white light when added together. E) are right for each other.
D) produce white light when added together.
43) On a planet where atmospheric gases are red, distant dark colored hills would look A) bluish. B) greenish. C) yellowish. D) reddish. E) untinted.
D) reddish.
An object is propelled along a straight-line path by a force. If the net force were doubled, the object's acceleration would be A) half as much. B) none of these C) the same. D) twice as much. E) four times as much
D) twice as much.
direct current
DC always flows in one direction
Discrete radii and energy states of atoms were first explained by electrons circling the atom in an integral number of diffraction patterns. de Broglie wavelengths. high-speed particles. wave frequencies. none of the above
De Broglie wavelengths
What is the unit for sound intensity?
Decibels (dB)
Your friend reasons that magenta and yellow paint mixed together will produce red because magenta is a combination of red and blue and yellow is a combination of red and green - and that the color in common is red. Do you agree or disagree, and why?
Disagree. Red is a primary color, it cannot be produced by mixing.
What two units of measurement are necessary for describing speed?
Distance and time
According to de Broglie, destructive interference occurs when an orbiting wave reinforces itself doesn't reinforce itself. neither of these
Doesn't reinforce itself
18) A mixture of red and green pigments appears A) orange. B) yellow. C) magenta. D) blue. E) blackish brown.
E) blackish brown.
If one object has twice as much mass as another object, it also has twice as much A) velocity. B) all of these C) acceleration due to gravity. D) volume. E) inertia.
E) inertia.
33) A red crab very deep in water, where sunlight is dim, appears A) red. B) orange. C) cyan. D) brown. E) no color - black.
E) no color - black.
What do each part in the equation E=hf stand for
E= energy of a photon h= Planck's constant f= frequency of vibrating photon aka - frequency characteristic of Quantum phenomenon gives smallest amount of energy that can be converted to light with the frequency f
In what way are magnetic poles very different from electric charges?
Electric charges can exist as singular entities, isolated. All magnets have both south and north poles. *breaking a bar magnet in half still creates a N and S end per piece!
What is the source of the magnetic force?
Electric charges in motion are the sources of magnetic forces.
What is the source of the magnetic force?
Electric charges in motion are the sources of magnetic forces; Force due to the motion of the charged paticles
What produces a magnetic field?
Electric charges in motion. Charged particles in motion have both an electric field and magnetic field associated with them. Charge is surrounded by magnetic field if it is moving.
The beam in a cathode-ray tube is composed of photons. electrons. both of these neither of these
Electrons
Why are electrons, rather than protons, the principal charge carriers in metal wires
Electrons are free to move through the metal, whereas protons are fixed in place.
Why are electrons, rather than protons, the principal charge carriers in metal wires?
Electrons are free to move through the metal, whereas protons are fixed in place. In metal wires, 1+ e- from each metal atom are free to move throughout the atomic lattice as *conduction electrons* white protons are bound inside nuclei. In *conducting fluids* like car batteries, positive ions are part of the charge flow.
At what speed do electrons in a battery driven automotive circuit travel along a wire? At what speed does the electric field propagate along a wire?
Electrons move at 0.01 cm/s. The electric field propagates at nearly the speed of light. In DC circuits, electrons have drift velocity, and the large numbers make large currents possible.
Some alpha particles fired at a gold foil bounced backward as a result of electrostatic repulsion by gold nuclei. reflection from the surfaces of gold atoms. electrostatic repulsion by electrons within gold atoms. all of the above none of the above
Electrostatic repulsion by gold nuclei
In photoelectric emission, the work function is the minimum energy an emitted electron possesses. frequency of light to produce emission. energy required to eject an electron from the surface. none of the above
Energy required to eject an electron from the surface
What do electric and magnetic fields contain and transport?
Energy. "Electric and magnetic fiends remain in perfect balance, reinforcing each other as they carry energy through space." pg.488
What two principal factors affect the force of air resistance on a falling object?
First, it depends on the frontal area of the falling object that is, on the amount of air the object must plow through as it falls. Second, it depends on the speed of the falling object.
When is your weight measured as mg?
For a non-accelerating mass near the surface of Earth
Frequency
For a vibrating body or medium, the number of vibrations per unit time. For a wave, the number of crests that pass a particular point per unit in time.
Why are metals shiny?
Free electrons in metals vibrate when light strikes them, thereby reemitting the light as reflected light.
Harmonics
Frequencies that are multiples of the fundamental frequency of a sound wave
What is the principal difference between a radio wave, light and X-ray?
Frequency
What is the wavelength of a wave that has a frequency of 1Hz and travels at 300,000 km/s?
Frequency = 1Hz = 1 wave/second Speed of wave = 300,000 km/s Length of wave = speed / frequency =300,000 km
you dip your finger repeatedly into a puddle of water and makes wave. What happens to the wavelength if you dip your finger more frequently?
From the equation for wave velocity (V=f~), increasing the frequency must decrease the wavelength in order to maintain a constant velocity
What is the weight of a 1-kilogram brick?
Fw=mg=(1kg)(10m/s²)=10N
What relationship between distance traveled and time did Galileo discover for freely falling objects released from rest?
Galileo discovered that distance increased as the time squared.
Which will NOT bend when moving in a magnetic field? gamma ray beta particle alpha particle all bend the same
Gamma ray
X-rays are similar to alpha rays. gamma rays. beta rays. all of the above none of the above
Gamma rays
How is the magnetic force on a particle moving in a magnetic field different from gravitational and electric forces
Gravitational and electric forces act along the line connecting two interacting objects, whereas magnetic forces are perpendicular to the motion of the particle and the magnetic field.
How is the magnetic force on a particle moving in a magnetic field different from gravitational and electric forces?
Gravitational and electric forces act along the line connecting two interacting objects, whereas magnetic forces are perpendicular to the motion of the particle and the magnetic field.
Consider an airplane that normally has an airspeed of 100 km/h in a 100-km/h crosswind blowing from west to east. Calculate its ground velocity when its nose is pointed north in the crosswind.
Ground velocity V = square root of [(100 km/h)squared + (100 km/h)squared] = 141 km/ h, 45° northeast (45° from the direction of the wind). The velocity relative to the ground makes the diagonal of a 45°-45°-90° triangle.
By whom, and in what setting, was the relationship between electricity and magnetism discovered?
Hans Christian Oersted in a classroom demonstration
By whom, and in what setting, was the relationship between electricity and magnetism discovered?
Hans Christian Oersted, in a classroom demonstration. (1820) An electric current affects a magnetic compass. (*ex in lab! Conservation of energy)
Which has lower energy quanta- red light or blue light? radio waves or X-rays?
Higher frequency, more energy X-rays deliver more energy than radio waves blue light more energy
Loudness
How loud humans hear a sound wave, determined from the wave's amplitude, measured in decibels (dB).
Lightbulb power and voltage reads 60W, 120V you can calculate the current that would flow by
I = P/V or (60Watt / 120Volts = 0.5Ampere)
if the voltage impressed across a circuit is held constant while the resistance doubles, what change occurs in the current
I = VR if R doubles then I (current) becomes 1/2 I~1/R
How is the fact that an electromagnetic wave in space never speeds up consistent with the law of conservation of energy?
If light speeded up, its energy would increase, thereby violating the law of conservation of energy. "The changing electric field would generate a stronger magnetic field; a crescendo of ever-increasing field strength and energy," a violation! In a vacuum, all electromagnetic waves move at the same speed and differ from one another in their frequency.
How is the fact that an electromagnetic wave in space never slows down consistent with the conservation of energy.
If light were to slow down in space the decreasing electric field would cause the magnetic field to lose energy as well. The decreasing electric and magnetic fields would cause the light to eventually die out and energy would not have been conserved. At the speed of light the mutual induction of the electric and magnetic fields cause the electromagnetic wave to neither gain or lose energy.
If molecules in the sky scattered low-frequency light more than high-frequency light, what color would the sky be? What color would sunsets be?
If low-freq light were scattered, noon skies would appear red-orange. At sunset, more reds would be scattered by longer path of sunlight, and sunlight would be predominantly blue and violet. Sunsets would appear blue!
If the mass of a sliding block is tripled while a constant net force is applied, by how much does the acceleration decrease?
If the net force is applied while the mass of the sliding block is tripled, then the mass is decreased by one and a half.
Distant dark mountains are bluish. What is the source of this blueness?
If we look at distant dark mountains, very little light from them reaches us, and the blueness of the atmosphere between dominates. The blueness we think is the mountains is actually the low-altitude "sky" between the mountains and us!
An apple hanging from a limb has potential energy because of its height. If it falls, what becomes of this energy just before it hits the ground? When it hits the ground?
Immediately before the apple hits the ground, its initial PE becomes KE. When it hits the ground its energy becomes thermal energy.
6 sec; 0.167 Hertz
In 60 seconds 10 wave crests pass by. The period is _____ and the frequency is _____.
transverse wave
In a _____, the wave vibration (oscillation) is at right angles to the direction the wave is traveling.
If a Mack truck and Honda Civic have a head-on collision, upon which vehicle is the impact force greater? Which vehicle experiences the greater deceleration? Explain your answers.
In accord with Newton's 3rd law, the force on each will be of the same magnitude. But the effect of the force (acceleration) will be different for each because of the different mass. The more massive truck undergoes less change in motion than the Civic.
At the micro level, what is the difference between an unmagnetized iron nail and a magnetized iron nail?
In an unmagnetized nail, the magnetic domains have a random orientation so that the net magnetism adds to zero. In a magnetized nail, many of the magnetic domains are aligned.
At the micro level, what is the difference between an unmagnetized iron nail and a magnetized iron nail?
In an unmagnetized nail, the magnetic domains have a random orientation so that the net magnetism adds to zero. In a magnetized nail, many of the magnetic domains are aligned. Bringing a magnet nearby (or electrically charged rod) will cause alignment, and normal thermal motion will cause them to return to random arrangement when removed.
When frequency increases, what does pitch do?
Increases
Why are infrared waves often called heat waves?
Infrared waves are called heat waves because they cause entire atoms and molecules to vibrate when they encounter an object. The vibration of the atoms and molecules increases the internal energy and temperature of the object.
What kind of speed is registered by an automobile speedometer?
Instantaneous speed
Light behaves primarily as a particle when it travels from one place to another. interacts with matter. both of these neither of these
Interacts with matter.
standing wave
Interference between an incident (incoming) wave and reflected wave results in a _____ which appears not to be traveling.
What does it mean to say that a certain current is 60 Hz?
It alternates back and forth 60 times a second.
What property of a diode enables it to convert ac to pulsed dc?
It is a one-way valve that allows electrons to in one direction only. Currents pass through a diode only half of each period, since alternating current changes its direction each half-cycle.
If the resistance of a circuit remains constant while the voltage across the circuit decreases to half its former value, what change occurs in the current?
It is cut in half. "the greater the voltage, the greater the current" ∴ "the smaller the voltage, the smaller the current"
If the voltage impressed across a circuit is held constant while the resistance doubles, what change occurs in the current?
It is cut in half. current = voltage/resistance amperes = volts/ohms "the greater the voltage, the greater the current) (the greater the resistance, the smaller the current)
When the speed of a moving car is doubled, how much more kinetic energy does it have?
It is quadrupled because 1/2 mv squared
If Earth shrank, but there was no change in its mass, then what would happen to your weight at the surface?
It would increase
All deposits of natural uranium contain appreciable amounts of lead. gold. iron. all of the above none of the above
Lead
About how much of the measured electromagnetic spectrum does light occupy?
Less than 1 millionth of 1%, a tiny fraction of the spectrum! Lowest frequency of light visible to us is red, with highest of violet. *roygbiv
The formula (change)p(change) x(greater than or equal to) h tells us that the product of (change)p and (change)x cannot be less than h greater than h equal to h
Less than h
Why do wet objects normally look darker than the same objects when dry?
Light bounces around inside the transparent water region covering a wet object, getting absorbed more on each bounce. Incident light on dry surfaces bounce directly to your eye.
Once the crate is sliding, how hard do you push to keep it moving at constant velocity?
Like stated before, the force you need to exert would have to equal the opposing force of friction.
What is the color of visible light of the lowest frequencies? Of the highest frequencies?
Lowest frequency of light visible to us is red, with highest of violet. *roygbiv
If you look with a magnifying glass at pictures printed in full color in this or other books or magazines, you'll notice three colors of ink plus black. What are these colors?
Magenta, cyan, and yellow
What are the subtractive primary colors?
Magenta, cyan, and yellow
An excited hydrogen atom is capable of emitting radiation of a single frequency. three frequencies. many more than three frequencies.
Many more than three frequencies
What relationship does mass have with weight?
Mass and weight often get confused with each other. People believe that mass (which is the matter of things) often means the same thing as weight (their gravitational attraction to the Earth). These two concepts are totally different things.
What was discovered in atomic spectra by physics pioneers Balmer, Rydberg, and Ritz? electrons behave as standing waves electrons occupy well-defined shells about the atomic nucleus unexplained randomness all atoms are about the same size mathematical order
Mathematical order
Why are metals shiny?
Metals are shiny because their outer electrons are not bound to any particular atom. These free electrons do not pass on the vibrations from the light to the atoms. This causes the light to be reflected making it shiny.
The Bohr model of the atom is akin to a blob of plum pudding, where raisins represent electrons. central heavy ball with lighter balls connected by springs. miniature solar system. all of the above
Miniature solar system
Would the spring inside bathroom scale be more compressed or less compressed if you weighed yourself in an elevator that moved upward at constant velocity? Downward at constant velocity?
More compressed going up. Less compressed going down.
Would the springs inside a bathroom scale be more compressed or less compressed if you weighed yourself in an elevator that was accelerating upward? Downward?
More compressed while accelerating upward, but less compressed while accelerating downward
Why is sound louder when a vibrating source is held to a sounding board?
More surface is forced to vibrate and push more air
The natural background radiation we personally encounter is more than half. a trace amount. about a quarter. about half.
More than half
The force between electrically charged particles depends on the magnitude of each charge, their separation distance, and what else?
Motion of electrically charged particles. Coulomb's Law (magnitude and distance). electric force and magnetic force; Sourced from the motion of particles.
What is meant by free fall?
Motion under the influence of gravitational pull only.
Why does a wire that carries electric current become hot?
Moving electrons collide with atoms, which transfers their kinetic energy to atomic motion.
Why does a wire that carries electric current become hot?
Moving electrons collide with atoms, which transfers their kinetic energy to atomic motion. "Bumping into" the anchored metallic ions in the path of e- makes the current-carrying wire hot.
Newton viewed the curving of the path of a planet as being caused by a force acting on the planet. How did Einstein view the curved path of a planet?
Moving in curved 4-dimensional spacetime
Why do wet objects normally look darker than the same objects when they are dry
Multiple reflections absorb light, and the light that emerges is weaker
A photosensitive surface is illuminated with both blue and violet light. The light that causes the greater number of ejected electrons is violet light. blue light. both eject equal numbers. need more information
Need more information
In casually observing a cup of tea you are affecting its location. affecting its temperature. both of these neither of these
Neither of these
What was the cause of perturbations discovered in the orbit of the planet Uranus? What later discovery did this lead to?
Neptune caused the perturbations, and later Pluto was discovered
When G was first measured by Henry Cavendish, newspapers of the time hailed his experiment as the "weighing of Earth experiment." why?
Newtons law of universal gravitation allowed the mass of the Earth to be calculated.
Distinguish between an umbra and a penumbra.
No light from the source enters the shadow in an umbra, while some, but not all, light from the source enters the penumbra.
Can you physically touch a person without that person touching you with the same amount of force?
No, touching requires a two-ness; the toucher and the touchee
When, if ever, can a vector quantity be added to a scalar quantity?
No. A vector quantity and scalar quantity can never be added.
Would a torque on the Moon occur if the Moon were spherical, with both its center of mass and center of gravity in the same location? Why?
No. The torque requires a distance between the center of mass and the center of gravity
The discreteness of energy levels is best understood by considering the electrons to be attached to the nucleus by massless springs. like tiny planets orbiting a sun. much less massive than the nucleus. all of the above none of the above
None of the above
When thorium (A = 90) emits a beta particle, the resulting nucleus has atomic number 89. 92. 90. 88. none of the above
None of the above
A quantum of light is called a proton. a neutrino. an electron. a neutron. none of the above
None of the above / PHOTON
In the photoelectric effect, the brighter the illuminating light on a photosensitive surface, the greater the velocity of ejected electrons. number of ejected electrons. both of these neither of these
Number of ejected electrons
What is the unit of electrical resistance?
Ohm (Ω) , after Georg Simon Ohm (1826) discovered relationship in voltage, current, resistance
For an isotope with a half-life of one day, at the end of three days the amount that remains is none. one-eighth. one-half. one-quarter. none of the above
One-eighth
When is the potential energy of something significant?
PE is significant when it changes, does work, or transforms to energy of another form.
In what direction relative to a magnetic field does a charged particle move in order to experience maximum deflecting force? To experience minimum deflecting force?
Perpendicular for maximum force, parallel for minimum force
In what direction relative to a magnetic field does a charged particle move in order to experience maximum deflecting force? To experience minimum deflecting force?
Perpendicular for maximum force, parallel for minimum force. "The force is strongest when the current is perpendicular to the magnetic field lines. The direction of force is not along the magnetic field lines or along the direction of current. The force is perpendicular to both field lines and current. It is a a sideways force."
The phenomenon easily explained only in terms of the particle model of light is photoelectric effect. refraction. diffraction. reflection. none of the above
Photoelectric effect
The ratio of the energy of a photon to its frequency is unknown. photon wavelength. Pi photon speed. Planck's constant.
Planck's Constant
What is the relationship among electric power, current, and voltage?
Power is current times voltage.
What is the relationship among electric power, current, and voltage?
Power is current times voltage. Watts = amperes X volts rate at which electric energy is converted into another form, ie mechanical energy, heat, light
When you make your household electric payment at the end of the month, are you billed for voltage, current, power, or energy?
Power utilities sell *energy*, while you supply the electrons. Energy flows from the outlet into the lamp, not electrons.
Using the Schrödinger equation, scientists can calculate the position of an electron. probabilities. the velocity of an electron. all of the above
Probabilities
What are the principal differences between a radio wave and light? Between light and an X-ray?
Radio waves have a lower frequency and longer wavelength than visible light waves. Light waves have a lower frequency and longer wavelength than X-rays. On spectrum, Radio Waves << visible light << X-rays
Two pulses of light, one red and one blue, have the same energy. The pulse with the greater number of photons is the blue pulse. red pulse. both the same
Red pulse
Is a mirage the result of reflection or refraction? Why does it happen?
Refraction. Light curves through warm, low-density air near the ground, where it travels faster.
When the nucleus of an atom emits only a gamma ray, the atom's atomic number increases. remains unchanged. decreases.
Remains unchanged
After passing through double slits, electrons make a pattern on a screen that resembles a pattern that waves make. has two peaks of intensity. has a single wide peak of intensity. shows which slit each electron has passed through.
Resembles a pattern that waves make.
What is the relationship between forced vibration and resonance?
Resonance occurs when the frequency of a forced vibration on an object matches the object's natural frequency and an increase in amplitude occurs.
What two kinds of motion do electrons in an atom appear to have?
Revolution and spin. Electrons revolve about the atomic nucleus and spin about their own axes like tops. In most common magnets, electron spin is the chief contributor to magnetism.
Distinguish between the rods and cones of the eye and between their functions
Rods handle vision in low light. The cones are used to detect color and handle vision in bright light.
Joule
SI unit of heat. 1 calorie = 4.184 of these
Which device is used primarily to detect nuclear radiation? scintillation counter synchrotron cyclotron linear accelerator none of the above
Scintillation counter
According to the Bohr model, an electron in an excited state of hydrogen can emit at most a single photon until the atom re-excites. a continuous stream of light. several photons in a series of transitions to a lower state. none of the above
Several photons in a series of transitions to a lower state
Natural frequency depends on what two properties?
Shape and elasticity
Artificially induced radioactive elements generally have no half-lives. short half-lives. long half-lives.
Short half-lives
Why does the use of blue light make it possible to store more information on a DVD?
Shorter-wavelength blue light can be focused to a smaller spot, allowing more bits to fit in the same area
If you push a magnet into a coil, you'll feel a resistance to your push. Why is this resistance greater in a coil w/ more loops?
Simply put, more work is required to provide more energy. When your push a magnet into a coil, you induce electric current and cause the coil to become an electromagnet. The more loops in the coil, the stronger the electromagnet that you produce and the stronger it pushes back against you.
How could you use the spotlights at a play to change the performers' clothes suddenly from yellow to black?
Since Yellow light = red + green, use Blue light to change to black (red + green + blue = black)
Only some of the people on the daytime side of Earth can witness a solar eclipse when it occurs, whereas all the people on the nighttime side of Earth can witness a lunar eclipse when it occurs. Why is this so?
Since the shadow of the relatively small moon on the large Earth covers a very small part of Earth's surface, only relatively few people are in the shadow of the moon during a solar eclipse. But the shadow of Earth that covers the moon during a lunar eclipse is in view of everybody who can see the moon in the nighttime sky. Sun>>moon>>Earth = small shadow (Solar) Sun>>Earth>>moon = large shadow (Lunar)
What mediums can sound travel through? Fastest medium? Slowest medium?
Sound can travel through gases (slowest), solids (fastest), and liquids.
Is sound intensity objective or subjective? What about loudness?
Sound intensity is objective and measured by instruments. Loudness is a physiological sensation sensed in the brain.
mechanical wave
Sound needs a medium to travel through, therefore it is a type of ____ ____.
How does air temperature affect the speed of sound?
Sound travels faster at higher temperatures
How does the speed of sound in air compare with its speed in water or steel?
Sound travels faster in water and steel
longitudinal
Sound waves are _____ waves.
How does speed affect the friction between a road and a skidding tire?
Speed has little or no effect on friction.
Why is speed considered a scalar and velocity a vector?
Speed has no direction just a quantity (magnitude). Velocity has both a quantity (magnitude) and a direction.
Which has the higher tides: spring tides or neap tides? Why?
Spring tides are higher, because the tides from the Moon and Sun add together
Distinguish between spring tides and neap tides
Spring tides are when the Earth, Moon and Sun are aligned and the difference between the high and low tides are greater. The neap tides are when the moon is at first or last Quarter (halfway between full moon and new moon). The difference between the high and low tides are less because the pull of the moon and sun partly cancel each other out.
Why can't we see stars in the daytime?
Stars do glow during the day, but we can't see them because of the glare of sunlight. When the sun is up, the blue color in sunlight gets scattered all over the atmosphere, turning the sky the familiar bright blue color. Intensity of the sun's light is far greater than that of the stars, as their intensity decreases by distance
Bimetallic strip
Strip consisting of two different metals that expand at different rates and cause the strip to bend; switch in a thermostat
Distinguish between monochromatic light and sunlight.
Sunlight has a wide range of frequencies and wavelengths, whereas monochromatic light has one wavelength and one frequency (filtered, though still incoherent, out of phase waves).
A heavy bird sits on a clothesline. Will the tension in the clothesline be greater if the line sags a lot or if it sags a little?
Tension will be greater for a small sag. That's because large vectors in each side of the rope supporting the bird are needed for a resultant that is equal and opposite to the bird's weight.
How does the lifetime of a typical CFL compare with the lifetime of an incandescent bulb?
The CFL lasts more than 10 times longer. Similar to a mini incandescent, coiled, with a gas filled tube, and magnetic or electronic ballast. Still contains mercury. Offers 4X the light.
Why is there a Doppler effect when the source of sound is stationary and the listener is in motion? In which direction should the listener move to hear a higher frequency? A lower frequency?
The Doppler effect is produced by the relative motion of the wave emitter and receiver. If the crest arrive sooner than the source emitted them there will be an increase in frequency. If the crests arrive less frequently than the source emitted them there will be a decrease in frequency.
How can astrophysicists tell whether a star is receding from or approaching Earth?
The Doppler shift of spectral lines is red for receding and blue for approaching. Measure the frequency emitted by the source, not the speed.
What is the cause of the aurora borealis (the northern lights)?
The Earth's magnetic field guides trapped charged particles to follow field lines (corkscrew paths) toward the poles, where they collide with the atmosphere, causing a glow.
What is the cause of the aurora borealis (the northern lights)?
The Earth's magnetic field guides trapped charged particles to follow field lines toward the poles, where they collide with the atmosphere, causing a glow.
how many vibrations per second are represented in a radio wave of 101.7 MHZ?
The M represents million and HZ represents vibrations per second, therefore we have the frequency of 101.7 million vibrations per second
Describe how the gravitational forces from the Sun and the Moon compare from one side of Earth to the other
The Sun exerts stronger force on the side of Earth nearest the Sun, and the Moon exerts a stronger force on the side nearest the Moon
medium
The _____ is the matter through which a wave travels.
If the net force acting on a sliding block is somehow tripled, by how much does the acceleration increase?
The acceleration would also be tripled. Acceleration is directly proportional to the net force
Cite the law of reflection
The angle of incident equals the angle of reflection.
How does the angle at which a ray of light strikes a pane of window glass compare with the angle at which it passes out the other side?
The angles are the same
A rocket becomes progressively easier to accelerate as it travels through space. Why is this so? (Hint: About 90% of the mass of a newly launched rocket is fuel.)
The answer is given in the equation a = F/m. As fuel is burned, the mass of the rocket becomes less. As m decreases as F remains the same, a increases! There is less mass to be accelerated as fuel is consumed.
How does the average speed of light in glass compare with its speed in a vacuum?
The average speed of light in glass is about 67% of the speed of light in a vacuum. Speed of light in a vacuum is constant 300,000 km/s. (*c*) In glass, speed is 0.67*c* In water, speed is 0.75*c* In diamond, speed is 0.41*c*
What did Galileo discover about the amount of speed a ball gained each second when rolling down an inclined plane? What did this say about the ball's acceleration?
The ball had constant acceleration, so it gained the same speed every second.
Distant snow-covered mountains reflect a lit of light, bright. Very distant ones look yellowish. Why?
The blue in the white light reflected is scattered on the way to us. By then, it is weak in high frequency, strong in low frequency. Hence, yellow. Further snow-covered mountains have an orange tinge, same as sunsets appear orange.
Compared with a car moving at some original speed, how much work must the brakes of a car supply to stop a car that is moving twice as fast? How will the stopping distances compare?
The brakes must supply four times as much work. There is four times as much stopping distance (as 2 squared = 4).
What was the cause of perturbations discovered in the orbit of the planet Uranus? What greater discovery did this lead to?
The cause of the perturbations of Uranus' orbit was the orbit of the undiscovered planet Neptune. Further observations of the orbits of Uranus and the newly discovered planet Neptune led to the discovery of Pluto in 1930 by Clyde Tombaugh at the Lowell Observatory in Arizona.
What is the effect on the color of a cloud when it contains an abundance of large droplets?
The cloud becomes dark
You can get a sunburn on a cloudy day, but you can't get a sunburn even on a sunny day if you are behind glass. Explain.
The clouds allow UV light to pass through, but glass does not allow UV light to pass through. Glass only lets in visible light.
Absolute Zero
The coldest temperature, 0 Kelvin, that can be reached. It is the hypothetical temperature at which all molecular motion stops.
What do the various colors displayed in the flame of a burning log indicate?
The colors of the flames indicate the types of atoms that are emitting light in the flame. Ex. salt in a flame produces characteristic yellow of sodium.
Why are there probably no permanently aligned magnetic domains in Earth's core?
The core is too hot to allow atoms to maintain a constant magnetic orientation.
Why are there probably no permanently aligned magnetic domains in Earth's core?
The core is too hot to allow atoms to maintain a constant magnetic orientation. *Temperature affects alignment!
A proton moves in a circular path perpendicular to a constant magnetic field. If the field strength of the magnet is increased, does the diameter of the circular path increase, decrease, or remain the same?
The diameter of the circular path decreases. Why?
Wavelength
The distance between successive crests, troughs, or identical parts of a wave
What is the focal length of a lens? What is the focal point?
The distance between the center of the lens and either focal point is the focal length. The focal point is the point where a beam of parallel light, parallel to the principal axis, converges or appears to converge.
What do electric and magnetic fields contain and transport?
The electric and magnetic fields contain and transport energy
Why does a piece of iron in a current-carrying loop increase the magnetic field strength?
The electromagnetic field of the current-carrying loop is amplified because it aligns the domains in the iron.
Why does a piece of iron in a current-carrying loop increase the magnetic field strength?
The electromagnetic field of the current-carrying loop is amplified because it aligns the domains in the iron. Industrial magnets do this to gain additional strength, increase the current through the coil.
An electron and a proton are traveling at the same speed. Which has the longer wavelength? the proton the electron both the same none of the above
The electron
Where do the electrons come from that produce an electric shock when you touch a charged conductor?
The electrons originate in your body. Energy passes through your body, causing free electrons to vibrate in unison.
How is the energy of a photon related to its vibrational frequency?
The energy is proportional to the frequency. E~f "The frequency of the photon is directly proportional to its energy. E=hf (Planck's)
What is the fate of the energy in ultraviolet light and infrared light that is incident upon glass?
The energy of the ultraviolet light (UV) and infrared is given up as heat and will not pass through glass. Therefore, glass is not transparent to UV light
What is the fate of energy that is in visible light that is incident on glass
The energy of vibrating electrons is reemitted as light after a slight delay. Glass is transparent to all the frequencies of visible light.
Heat
The energy that transfers from one object to another because of a temperature difference between them.
disturbance in the medium
The energy transferred by a wave is carried by a _____.
Why is a black hole invisible?
The escape velocity of the black hole is greater than the speed of light
How does magnetic field strength relate to the closeness of magnetic field lines about a bar magnet?
The field strength is stronger where the field lines are closer.
How does magnetic field strength relate to the closeness of magnetic field lines about a bar magnet?
The field strength is stronger where the field lines are closer. Magnetic field lines spread out from one pole (N) and return to other (S). Concentrations of iron filings at the poles show that strength is greater there, where lines gather.
How does the force of gravity between two bodies change when the distance between them is doubled?
The force decreases to 1/4 of its initial value
State Newton's law of universal gravitation in words. Then do the same with one equation
The force is proportional to the product of two masses and inversely proportional to the square of the distance between their center: F ~ m1m2/d^2
Identify the force that propels a rocket.
The force that propels a rocket is the reaction to the force the rocket exerts on the exhaust gases.
A farmer urges his horse to pull a wagon. The horse refuses, saying that to try would be futile, for it would flout Newton's third law. The horse concludes that she can't exert a greater force on the wagon than the wagon exerts on her and therefore, that she won't be able to accelerate the wagon. What is your explanation to convince the horse to pull?
The forces do not cancel because they act on different things—one acts on the horse, and the other acts on the wagon. It's true that the wagon pulls back on the horse, and this prevents the horse from running as fast as it could without the attached wagon. But the force acting on the wagon (the pull by the horse minus friction) divided by the mass of the wagon, produces the acceleration of the wagon. To accelerate, the horse must push against the ground with more force than it exerts on the wagon and the wagon exerts on it. So tell the horse to push backward on the ground.
Two people of equal mass attempt a tug-of-war with a 12-m rope while standing on frictionless ice. When they pull on the rope, each of them slides toward the other. How do their accelerations compare, and how far does each person slide before they meet?
The forces on each are the same in magnitude, and their masses are the same, so their accelerations will be the same. They will slide equal distances of 6 meters to meet at the midpoint.
How does the frequency of reemitted light in a transparent material compare with the frequency of light that stimulated its reemission?
The frequencies are the same
What does it mean to say that everything has a natural frequency of vibration?
The frequency is characteristic of the object's shape, size, and composition
The intensity of light decreases as the inverse square of the distance from the source. Does this mean that light energy is lost? Explain.
The frequency of reemitted light is identical to the frequency of incidental light. At this speed, energy is carried forward withouth loss or gain. There is a time delay between absorption and reemission. It is this time delay that results in a lower average speed of light through a transparent material.
If you exert a horizontal force of 200 N to slide a crate across a factory floor at constant velocity, how much friction is exerted by the floor on the crate? Is the force of friction equal and oppositely directed to your 200-N push? If the force of friction isn't the reaction force to your push, what is?
The friction on the crate is 200 N, which cancels your 200-N push on the crate to yield the zero net force that accounts for the constant velocity (zero acceleration). Although the friction force is equal and oppositely directed to the applied force, the two do not make an action-reaction pair of forces. That's because both forces do act on the same object—the crate. The reaction to your push on the crate is the crate's push back on you. The reaction to the frictional force of the floor on the crate is the opposite friction force of the crate on the floor.
If you hold any small source of white light between you and a piece of red glass, you'll see two reflections from the glass; one from the front surface and one from the back. What color is each reflection?
The front surface reflection is white because the light doesn't go far enough into the colored glass to allow the absorption of nonred light. Only red light reaches the back surface because the pigments in the glass absorb all other colors; the back reflection is red.
For a planet of uniform density, how would the magnitude of the gravitational field halfway to the center compare with the field at the surface?
The gravitational field halfway to the center will be half of the gravitational field at the surface.
What happens to the strength of the gravitational field at the surface of a star that shrinks?
The gravitational field strength at the surface of a shrinking star increases in a manner that follows the inverse square law. The gravitational field at the surface of a star that has a radius half the size as before will have a gravitational field 4 times as strong at the surface.
How does a helicopter get its lifting force?
The helicopter blades force air downward, and in doing so the air forces the blades upward. The upward force provides lift.
Faster
The higher the temperature of the air, the (slower or faster?) the sound wave travels.
Relative to the distance of an object in front of a plane mirror, how far behind the mirror is the image?
The image is the same distance behind the plane mirror as the object is in front of it.
What is the refraction and the speed of light in a material?
The index of refraction is inversely proportional to the speed of light in a material.
State Faraday's law.
The induced voltage in a coil is proportional to the number of loops, multiplied by the rate at which the magnetic field changes w/in those loops
How does interference of sound relate to beats?
The interference of two sound sources of slightly different frequencies produces beats.
constructive interference
The interference that occurs when two waves combine to make a wave with a larger amplitude
the period
The inverse of the frequency is _____ _____.
When red light shines on a red rose, why do the leaves become warmer than the petals?
The leaves absorb the energy of the red light, rather than reflect it, and so become warmer. They are not red, so they do not reflect it!
The sound coming from one tuning fork can force another to vibrate. What is the analogous effect for light?
The light emitted by resonant vibrations of an electron around one atom can be absorbed by an electron with the same resonant frequency of vibration in another atom. "Vibrations in the emitter are transmitted to vibrations in the receiver."
When the wheel of a cart rolls from a smooth sidewalk onto a plot of grass, the interaction of the wheel with the blades of grass slows the wheel. What slows light when it passes from air into glass or water?
The light oscillates electrons in the atoms of the glass or water. The electron absorb some of the energy and reemit it after a delay at each atom
Why does the Sun look reddish at sunrise and sunset but not at noon?
The longer path length of sunlight at sunrise and sunset scatters out more blue light. At noon, sunlight travels through the least amount of atmosphere to reach Earth. Only a small amount of high-frequency light is scattered, to make the Sun look yellow.
Sonic Boom
The loud sound that results from the incidence of a shock wave
Slower
The lower the temperature of the air, the (slower or faster?) the sound wave travels.
Fundamental Frequency
The lowest frequency from a standing wave in a harmonic
In Chapter 22, we learned that the direction of the electric field about a point charge is radial to the charge. What is the direction of the magnetic field surrounding a current-carrying wire?
The magnetic field is directed along concentric circles surrounding the wire.
In Chapter 22, we learned that the direction of the electric field about a point charge is radial to the charge. What is the direction of the magnetic field surrounding a current-carrying wire?
The magnetic field is directed along concentric circles surrounding the wire. (like rings around the wire). If the wire is bent in a loop, the field bunches up as well (Fig.24.9)
Why is the magnetic field strength greater inside a current-carrying loop of wire than about a straight section of wire
The magnetic field of each segment of wire in the loop, due to electrons moving in the wire, adds together inside the loop, thereby making the field become bunched-up.
Why is the magnetic field strength greater inside a current-carrying loop of wire than about a straight section of wire?
The magnetic field of each segment of wire in the loop, due to electrons moving in the wire, adds together inside the loop, thereby making the field become bunched-up.
What happens to the direction of the magnetic field about an electric current when the direction of the current is reversed
The magnetic field reverses direction at every point. A clockwise pattern of concentric circles becomes a counterclockwise pattern of concentric circles and vice versa.
What happens to the direction of the magnetic field about an electric current when the direction of the current is reversed?
The magnetic field reverses direction at every point. A clockwise pattern of concentric circles becomes a counterclockwise pattern of concentric circles and vice versa.
All atoms have moving electric charges. Why, then, aren't all materials magnetic?
The magnetic fields of individual iron atoms are strong enough to align the magnetic fields of neighbor atoms. The atoms in wood have much weaker magnetic fields.
What is meant by drift velocity?
The net flow of electrons along a wire.
What is meant by drift velocity?
The net flow of electrons along a wire. When an electric field is applied, interrupting e- motion, the electron drifts toward the right, very slow.
Interference Pattern
The pattern formed by the superposition of different sets of waves that produces reinforcement in some places and cancellation in others
How is the peak frequency of emitted light related to the absolute temperature of its incandescent source?
The peak frequency is proportional to the absolute temperature. f=T
seconds
The period of a wave is measured in _____.
When green light shines on a rose, why do the petals look black?
The petals absorb rather than reflect the green light. Because green is the only color illuminating the rose and green contains no red to be reflected, the rose reflects no color and appears black.
Wave Interference
The phenomenon that occurs when two waves meet while traveling along the same medium
The physics underlying photovoltaic solar cells is electron diffraction. photon capture. the photoelectric effect. none of the above
The photoelectric effect
What are magnetic pole reversals?
The poles of the Earth's magnetic field undergo reversals.
Consider hitting a baseball with a bat. If we call the force on the bat against the ball the action force, identify the reaction force.
The reaction force is the ball hitting the bat.
What aspect of physics was not known by the writer of this newspaper editorial that ridiculed early experiments by Robert H. Goddard on rocket propulsion above Earth's atmosphere? "Professor Goddard . . . does not know the relation of action to reaction, and of the need to have something better than a vacuum against which to react . . . he seems to lack the knowledge ladled out daily in high schools."
The relation of action to reaction. The law of action and reaction is precisely how a rocket works in a vacuum. It pushes out gas in one direction, and gets an equal and opposite momentum in the other direction.
According to the parallelogram rule, what quantity is represented by the diagonal of a constructed parallelogram?
The resultant of the vectors that make up the sides of the parallelogram.
How do the rods in the eye differ from the cones?
The rods are rod-shaped and are more sensitive to dim light; cluster in periphery. The cones are cone-shaped and are color-sensitive; cluster near fovea
Two 100-N weights are attached to a spring scale as shown. Does the scale read 0, 100, or 200 N, or does it give some other reading? (Hint: Would it read any differently if one of the ropes were tied to the wall instead of to the hanging 100-N weight?)
The scale will read 100 N, it would read the same if one of the ends were tied to a wall instead of tied to the 100-N hanging weight. Although the net force on the system is zero, the tension in the rope within the system is 100 N, as shown on the scale reading.
The acceleration of free fall is about 10 m/s2. Why does the seconds unit appear twice?
The second appears once in the denominator of the unit for speed and once for the interval of time.
forced vibration
The setting up of vibrations in an object by a vibrating force.
Doppler Effect
The shift in received frequency due to the motion of a vibrating source toward or away from a receiver
What is the source of energy in sunshine?
The source of the energy of sunshine is fusion power in the Sun.
What is the speed acquired by a freely falling object 5 s after being dropped from a rest position? What is the speed 6 s after?
The speed is 50 m/s after 5 s and 60 m/s after 6 s.
Wave Speed
The speed with which waves pass a particular point: wave speed = frequency x wavelength
Thermal Equilibrium
The state of two or more objects or substances in thermal contact when they have reached a common temperature
What relationship did Galileo discover about a ball's acceleration and the steepness of an incline? What acceleration occurs when the plane is vertical?
The steeper the incline, the greater the acceleration. On a vertical incline, the ball is in free fall.
How do the currents through the branches of a simple parallel circuit compare with the current in the voltage source?
The sum of the currents in the branches equals the current through the source.
How do the currents through the branches of a simple parallel circuit compare with the current in the voltage source?
The sum of the currents in the branches equals the current through the source. The pathway for current from one terminal of the battery to the other is completed if only one lamp is lit. A break in any one path does not interrupt the flow of charge in the other paths.
Fahrenheit Scale
The temperature scale on which water freezes at 32°F and boils at 212°F.
In a tug-of-war between Sam and Maddy, each pulls on the rope with a force of 250 N. What is the tension in the rope? If both remain motionless, what horizontal force does each exert against the ground?
The tension in the rope is 250 N. Since they aren't accelerating, each must experience a 250-N force of friction via the ground. This is provided by pushing against the ground with 250 N.
Consider Nellie hanging at rest. If the ropes were vertical, with no angle involved, what would be the tension in each rope?
The tension on each rope would be half of Nellie's weight. Nellie has a mass of m (units: kilograms). Nellie is hanging from two vertical ropes on earth (thus g = 9.8 m/s^2) The downward force of Nellie is mg. The tension in the two ropes equals mg. Each rope holds half the tension. The tension in a roe is mg / 2.
The uncertainty principle tells us that the more information one has about the energy of an electron, the less certain one is about the time it has that energy. its position. both of these neither of these
The time it has that energy.
Two cars are raised to the same elevation on servicestation lifts. If one car is twice as massive as the other, compare their gains of potential energy.
The twice as massive car has twice the PE.
Distinguish between an umbra and penumbra
The umbra is the darker part of the shadow caused by an object blocking all light from passing through. The penumbra is the lighter parts of a shadow where not all light is blocked.
What is the Newtonian synthesis?
The union of terrestrial laws and cosmic laws
Bow Wave
The v-shaped disturbance created by an object moving across a liquid surface at a speed greater that the wave speed
What do we mean when we say that outer space is not really empty?
The vacuum of space is full of electromagnetic wave energy. "Montages of electromagnetic waves permeate every part of our surroundings; some are visible are light. Radio waves, free electrons, radiation is everywhere."
If you stand next to a wall on a frictionless skateboard and push the wall with a force of 30 N, how hard does the wall push on you? If your mass is 60 kg, show that your acceleration is 0.5 m/s2.
The wall pushes on you with 30 N. a = F/m = 30 N/60 kg = 0.5 m/s2.
An electron microscope makes use of the inertia of electrons. short wavelengths of light. electron current. the wave nature of electrons. electron attraction and repulsion.
The wave nature of electrons
The finding that electrons in an atom occupy a volume much greater than the volume of the nucleus is best explained by electromagnetic forces. relative sizes of electrons and nuclei. the wave nature of the electron. angular momentum conservation. none of the above
The wave nature of the electron
How is the wavelength of light related to its frequency?
The wavelength is inversely proportional to the frequency. "waves of low frequency have long wavelengths, and waves of high frequencies have short wavelengths."
Which team wins in a tug-of-war-the team that pulls harder on the rope, or the team that pushes harder against the ground? Explain.
The winning team pushes harder against the ground. The ground then pushes harder on them, producing a net force in their favor.
What relative direction between a magnetic field and a current-carrying wire results in the greatest force?
The wire should be perpendicular to the field.
The force between electrically charged particles depends on the magnitude of each charge, their separation distance, and what else?
Their motion
relationship does mass have with inertia?
There are times when weight corresponds to our unconscious notion of inertia. For example; If you are trying to determining which of two small objects is heavier, you could shake them back and forth in your hands or move then in some way instead of lifting them. In doing so, you are judging which of the two is more difficult to get moving; feeling which of the two is most resistant to a change in motion. You are really comparing the inertias of the two objects. Mass is a measure of the inertia of a material object.
Why is a secondary rainbow dimmer than a primary bow? how are the colors arranged in the secondary bow?
There is a second reflection with a loss of light. the colors are in the opposite order of the primary bow, with red on the inside instead of the outside
Would the springs inside a bathroom scale be more compressed or less compressed if you weighed yourself in an elevator that was moving upward at constant velocity? Downward at constant velocity?
There would be no more compression and no more expansion for both upward and downward motion
What occurs when the outer electrons that buzz about the atomic nucleus encounter electromagnetic waves?
They are forced into vibration, absorbing or emitting electromagnetic waves. Once vibrating, they send out their own em waves, just as tuning forks send out sound waves.
Why are occupants of the International Space Station weightless ?
They are in free fall
How does the frequency of a radio wave compare to the frequency of the vibrating electrons that produce it?
They are the same. "The frequency of a wave is the same as the frequency of the vibrating source that creates the wave." "The frequency of an electromagnetic wave as it vibrates through space is identical to the frequency of the oscillating electric charge that generates it."
How does the frequency of reemitted light in a transparent material compare with the frequency of the light that stimulates its reemission?
They are the same. "The frequency of the reemitted light is identical to the frequency of the incident light. However, slight time delay lowers average speed of light through a transparent material."
How does the speed of light that emerges from a pane of glass compare with the speed of light incident on the glass?
They are the same. The incident light is at speed *c* Through the glass, speed is 0.67*c* The emergent light is at speed *c* again.
Alpha particles are normally repelled by atomic nuclei because of oppositely-directed forces. they both have the same sign of electric charge. their closeness with atomic nuclei violates quantum rules. all of the above none of the above
They both have the same sign of electric charge
Why are red and cyan called complementary colors?
They can be added together to make white light.
Why do different objects make different sounds when dropped on a floor?
They have different natural frequencies
If raindrops fall vertically at a speed of 3 m/s and you are running at 4 m/s, how fast do they hit your face?
They hit your face with the resultant of the horizontal and vertical components: R = square root of [(3.0 m/s)squared + (4 .0 m/s)squared] = 5 m/s.
What do the electrons affected by illumination do when they are made to vibrate with greater energy?
They reemit more light or collide with neighbors, thereby converting light energy to more internal energy.
Are eyeglasses made with "high index of refraction" materials thinner or thicker? Why?
Thinner. Light bends more entering high index of refraction materials.
A tipped domino sends a pulse along a row of standing dominoes. Is this a good analogy for the way electric current, sound, or both travel?
This is a good model for sound travel but not how electric current travels. Electrons that are free to move in a conductor are accelerated by the electric field impressed upon them, not because they bump into one another. "Bumping" that does occur (drift) actually slows them down and offers resistance to their motion.
A tipped domino sends a pulse along a row of standing dominoes. Is this a good analogy for the way electric current, sound, or both travel?
This is the way sound travels but not how electric current travels.
Do tides depend more on the strength of gravitational pull or on the difference in strengths? Explain.
Tides depend only on the difference
Suppose a piano tuner hears 2 beats per second when listening to the combined sound from her tuning fork and the piano note being tuned. After slightly tightening the string, she hears 1 beat per second. Should she loosen or should she further tighten the string? Explain.
Tighten; she is approaching zero beats, meaning matched frequencies
A balloon floats motionless in the air. A balloonist begins climbing the supporting cable. In which direction does the balloon move as the balloonist climbs?
To climb upward means pulling the rope downward, which moves the balloon downward as the person climbs.
What is the function of fuse or circuit breaker in a circuit?
To prevent over loading the circuit with current
What is the function of fuse or circuit breaker in a circuit?
To prevent over loading the circuit with current. Fuses may be connected in a series along a supply line. This way the entire line current must pass through the fuse. Cautions are made to "blow out" the circuit.
At the beach you see a friend facing away from you. Keeping quiet you can cause her to turn around by although staring will be less effective, both will affect a turn-around. staring intently at her back. tossing small pebbles at her back. none of the above
Tossing small pebbles at her back
Gamma rays are emitted by way of transitions within the atomic nucleus. ionizing radiation. transitions within an atom's innermost electrons. none of the above
Transitions within the atomic nucleus
What can you correctly say about two vectors that add together to equal zero?
Two vectors that add together to be equal to zero must have the same magnitude (length) and the opposite direction.
In the electron-wave model of the atom, an electron in the second energy level contains a single wavelength. any number of wavelengths. two wavelengths. none of the above
Two wavelengths
Suppose three tuning forks of frequencies 260 Hz, 262 Hz, and 266 Hz are available. What beat frequencies are possible for pairs of these forks sounded together?
Two, four, and six Hz are the possible beat frequencies for pairs of these forks sounded together.
In what region of the electromagnetic spectrum is the resonant frequency of electrons in glass?
UV "UV shines on glass, resonance occurs and electrons vibrate to large amplitudes. Energy received by glass atoms is either reemitted or passed onto neighbor atoms by collision. Glass is not transparent to UV light."
What is the fate of the energy in ultraviolet light that is incident upon glass?
Ultraviolet light will be absorbed by the resonant vibration of electrons and turned into internal energy and a temperature increase. "Resonating atoms in glass hold onto UV light energy for a long time, and give up energy as heat."
In Heisenberg's formula, p x h, the symbolizes increase in. decrease in. change in. uncertainty of. certainty of.
Uncertainty of
The resulting atomic number of an element that emits 1 alpha particle, 1 positron, and 3 beta particles is unchanged. increased by 1. decreased by 1. increased by 2. decreased by 2.
Unchanged
Sound waves travel at approximately 340 m/s. What is the wavelength of a sound with a frequency of 20 Hz? What is the the wavelength of a sound with a frequency of 20 kHz?
V = λƒ 340 m/s = (20Hz)λ λ = 17 m 340 m/s = (20000Hz)λ λ = 0.017 m
what is the relationship among frequency , wavelength, and wave speed?
V=frequency x wavelength, therefore the wave's speed is directly proportional to its frequency and wavelength.
Which of the following are scalar quantities, which are vector quantities, and which are neither? (a) velocity (b) age (c) speed (d) acceleration (e) temperature.
Vector quantities are velocity and acceleration. All others are scalars.
What is the main difference between speed and velocity?
Velocity includes a direction, but speed does not.
A key feature of the theory of chaos is even orderly systems are seen to be disorderly when carefully studied. very small initial differences can lead to very large eventual differences. the randomness of molecular motion makes prediction difficult. unpredictability.
Very small initial differences can lead to very large eventual differences.
Why do opaque materials become warmer when light shines on them?
Vibrations given by the light to their electrons, atoms, and molecules that absorb the light become internal energy, thus leading to a temperature increase. "They absorb light without reemitting it. Vibrations turn into random kinetic energy."
Why will dropping an iron magnet on a concrete sidewalk make it a weaker magnet?
Vibrations provide energy to randomize the magnetic directions of the domains.
Why will dropping an iron magnet on a concrete sidewalk make it a weaker magnet?
Vibrations provide energy to randomize the magnetic directions of the domains. The domains are jostled out of alignment. Heating the magnet with do the same.
Which travels more slowly in glass, red light or violet light? Why?
Violet light travels slower because it is closer in frequency to the ultraviolet resonance of the atoms in the glass.
What is the fate of the energy in visible light that is incident upon clear glass?
Visible light will be transmitted by the glass, losing little energy in the process, so the energy remains visible light energy. "Glass is transparent to all frequencies of visible light, passing on reemitted light of same frequency as the incident light."
The rule stating that the sum of two emitted frequencies in an atomic spectrum equals a third frequency is attributed to the physicist W. Ritz. Max Planck. Einstein Niels Bohr.
W. Ritz
A sample of highly-radioactive material is somewhat warmer than the environment. cooler than the environment. neither of these
Warmer than the environment
Why does water appear cyan?
Water absorbs red light. White minus red is cyan.
What accounts for the whiteness of a cloud?
Water droplets of different sizes scatter a variety of light frequencies, resulting in a white cloud. The froth in waves is white because it also is composed of a variety of tiny water droplets, scattering light of all visible frequencies.
In the equation E = hf, the symbol f stands for rate at which photons are emitted. wavelength. wave frequency. none of the above
Wave frequency
Why electrons don't spiral into atomic nuclei is best explained by their particle nature. wave nature. both of these neither of these
Wave nature
Formula for Wave Speed
Wave speed (in meters per second) = wavelength (in meters) x frequency (in hertz)
meters/second
Wave speed (v) is measured in _____.
When watching a baseball game, we often hear the bat hitting the ball after we actually see the hit. Why?
We hear the bat hitting the ball before after we actually see the hit because light travels faster than sound.
it decreases
What happens to frequency when a wave source is moving away from an observer?
it increases
What happens to frequency when a wave source is moving toward an observer?
0.1 Hz
What is the frequency of a skyscraper that sways back and forth with a period of 10 seconds?
something that vibrates
What is the source of ALL waves?
When a sound wave propagates past a point in the air, what are the changes that occur in the pressure of air at this point?
When a sound wave propagates past a point in the air, the air pressure of this point decreases.
The sound coming from one tuning fork can force another to vibrate. What is the analogous effect for light?
When light is transmitted through matter, some of the electrons in the matter are forced into vibration. In this way, vibrations in the emitter are transmitted to vibrations in the receiver.
Acceleration is generally defined as the time rate of change of velocity. When can it be defined as the time rate of change of speed?
When moving in a straight line, the time rate of change of speed is acceleration.
If you drop a rubber ball on the floor, it bounces back up. What force acts on the ball to provide the bounce?
When the ball exerts a force on the floor, the floor exerts an equal and opposite force on the ball- hence bouncing. The force of the floor on the ball provides the bounce.
When the athlete holds the barbell overhead, the reaction force is the weight of the barbell on his hand. How does this force vary for the case in which the barbell is accelerated upward? Downward?
When the barbell is accelerated upward, the force exerted by the athlete is greater than the weight of the barbell (the barbell, simultaneously, pushes with greater force against the athlete). When acceleration is downward, the force supplied by the athlete is less.
When can a nonzero vector have a zero horizontal component?
When the direction of the vector is vertical. Gravitational force has zero horizontal component.
When is the angle at which a ray of light strikes glass not the same as the angle it exits?
When the light strikes the glass in one medium (such as air) and exits the glass in another medium (such as water)
Consider the system of a single football. If you kick it, is there a net force to accelerate the system? If a friend kicks it at the same time with an equal and opposite force, is there a net force to accelerate the system?
When there is one interaction between the foot and the football, the ball accelerates. If two kicks on the ball are simultaneous, equal, and opposite, then the net force on the ball is zero.
When are objects on the periphery of your vision most noticeable?
When they are moving. "The periphery is very sensitive to motion. We are wired to look for movement to the side of our visual field."
Distinguish between a converging and a diverging lens.
When two parallel rays of light pass through a converging lens, the rays bend towards each other. When they pass through a diverging lens, the rays move apart from each other.
in phase
When waves are _____, the crests of one wave overlap the crests of another (ditto for troughs) causing them to reinforce each other.
Will water flow more easily through a wide pipe or a narrow pipe? Will current flow more easily through a thick wire or a thin wire?
Wide pipe and thick wire
What is the error in saying the source of electrons in a circuit is the battery or generator?
Wires are full of mobile electrons.
What is the error in saying the source of electrons in a circuit is the battery or generator?
Wires are full of mobile electrons. "unlike buying a water hose empty of water, you cannot buy an electric wire empty of electrons. The conducting circuit material is the source of the electrons. Electrons do not flow from power lines!"
When G was first measured by Henry Cavendish, newspapers of the time hailed his experiment as the "weighing Earth experiment." Why?
With a known mass, a scale, and the radius of Earth, you can calculate the unknown mass of Earth if you know G.
To produce a net force on a system, must there be an externally applied net force?
Yes
Earth pulls down on you with a gravitational force that you call your weight. Do you pull up on Earth with the same amount of force?
Yes, You pull on the earth with exactly the same force that the earth pulls on you. Your effect on the earth is insignificant because acceleration = F/M.
Is it true that when you drop from a branch to the ground below, you pull upward on Earth? If so, then why is the acceleration of Earth not noticed?
Yes, it's true. The Earth can't pull you downward without you simultaneously pulling Earth upward. The acceleration of Earth is negligibly small, and not noticed, due to its enormous mass.
Do Earth and the Moon always cast shadows? What do we call the occurrence where one passes within the shadow of the other?
Yes, they both cast shadows. When one passes into the shadow of the other, there is an eclipse. Solar: Earth passes in Moon's shadow Lunar: Moon passes in Earth's shadow
In the figure we see a magnet exerting a force on a current-carrying wire. Does a current-carrying wire exert a force on a magnet? Why or why not?
Yes. Complementary links between electricity and magnetism: And Newton's Third Law! Applies to ALL forces in nature. If a current-carrying wire produces a force on a magnet, the magnet must produce a force on the wire.
Does the law of reflection hold for curved mirrors? Explain.
Yes. It is as if the curved mirror is made of many small plane mirrors at slightly different orientations to each other.
Is it correct to say that an electric motor extends the physics that underlies a galvanometer? Why?
Yes. The deflection forces are the same, but the direction of current in the motor is reversed cyclically
Is it correct to say that an electric motor extends the physics that underlies a galvanometer? Why?
Yes. The deflection forces are the same, but the direction of current in the motor is reversed cyclically. If the design of the galvonometer is changed slightly so the deflection makes a complete turn rather than a partial rotation, it becomes an electric motor. The principal difference is that the current in a motor is made to change direction each time the coil makes a half rotation
Can a surface be considered polished for some waves and not for others? Cite an example.
Yes. The mesh of a radio dish is polished for long wavelength radio waves and yet rough for short wavelength light waves.
When a pair of vectors are at right angles, is the resultant always greater in magnitude than either of the vectors separately?
Yes. When a pair of vectors are at right angles, the resultant is always greater than either of the vectors separately.
When you adjust a telescope to get a clear image of Saturn's rings, there is a perceptible interaction between you and Saturn's rings. you and the telescope. both of these neither these
You and the telescope
When you look at a distant galaxy through a telescope, how is it that you're looking backward in time?
You are seeing the delay for the light to reach your eye.
Where do you weigh more-at the bottom of Death Valley or atop one of the peaks of the Sierra Navada? Why?
You weigh more at the bottom of death valley, the distance to the center of the Earth is less than at the top of the mountain. If F = G((m1m2)/d and d is smaller, then the force of gravity. (F) is larger, causing you to weigh more.
Which theory of light: wave theory or particle theory did the findins of Young, Maxwell and Hertz support
Young- double slit experiment Maxwell- light carries energy in ocillating electric and magnetic fields Hertz- electromagentic waves - all wave theory -Newton believed in particle theory
Give an example of when your weight is more than mg. Give an example of when it's zero.
Your weight is greater than mg if the support force you are on is accelerating upward. Your weight is zero when there is no support force.
Give an example of when your weight is greater than mg. Give an example of when your weight is zero.
Your weight is greater than mg when you are accelerating upward. Your weight is zero when you are in free fall
What is the magnitude of the gravitational field at Earth center?
Zero N/kg
natural frequency
_______________________________________when matched by forced vibrations increases amplitude
A diode converts ac to pulsed dc. What electrical device smoothes the pulsed dc to a smoother dc?
a capacitor. The ac input of the diode is output as pulsating dc. The capacitor provides continuous, smoother current by slow charging and discharging.
shock wave
a cone-shaped wave produced by an object moving at supersonic speed through the medium (air for example)
sine curve
a curve whose shape represents the crests and troughs of a wave, as traced out by a swinging pendulum that drops a trail of sand over a moving conveyor belt
red shift
a decrease in the measured frequency of light from a receding source; the decrease is towards the low frequency end of the color spectrum
wave
a disturbance that repeats regularly in space and time and that is transmitted progressively from one place to the next with no actual transport of matter
natural frequency
a frequency at which an elastic object, once energized, will vibrate
interference pattern
a pattern formed by the overlapping of two or more waves that arrive in a region at the same time; results in an increased, decreased, or neutralized wave
parallelogram rule
a rule or regulation used to find the resultant of two vectors through construction of a parallelogram. The parallelogram has two adjacent sides or edges that represent the directions and magnitudes of the vectors.
how does a semiconductor differ from a conductor or an insulator
a semiconductor can be both conductor and insulator
standing wave
a stationary wave pattern formed in a medium when two sets of identical waves pass through the medium in opposite directions
Celsius Scale
a temperature scale that defines the freezing point of water as 0 degrees and the boiling point of water as 100 degrees
beats
a throbbing variation in the loudness of sound caused by interference when two tones of slightly different frequencies are sounded together
a. How fast does sound travel in dry air at room temperature? b. How does air temperature affect the speed of sound?
a. In dry air at room temperature, sound travels at about 340 m/s. b. For each degree increase in air temperature above 0 degrees C, the speed of sound in air increases by .6 m/s.
Materials generally become warmer when light is a. absorbed by them b. transmitted by them c. reflected by them d. all of the above e. none of the above
a. absorbed by them
Nellie Newton hangs motionless by one hand from a clothesline. Which side of the line, a or b, has the greater a. horizontal component of tension? b. vertical component of tension? c. tension?
a. horizontal component of tension - b. vertical component of tension - side a c. tension - side a
In a current carrying wire, collisions interrupt the motion of the electrons so that their
actual drift speed through the wire is extremely low
constructive interference
addition of two or more waves when wave crests overlap and reinforce each other to produce a wave of increased amplitude (reinforcement)
What 2 principal factors affect the force of air resistance on a falling object?
air resistance is proportional to (1)the objects velocity and (2)the objects surface area
What is the evidence for the statement that white light is a composite of all the colors of the spectrum?
all of these: If you shine white light through a glass filter passing any spectral color, then that color will come through the filter. White light can be separated into all colors of the spectrum using a prism, and then these colors can be recombined to make white light. In a rainbow, sunlight is spread into all the colors by passing through water drops.
As pitch of sound increases, what happens to the frequency?
also increases
If sound becomes louder, which wave characteristic is likely increased- frequency, wavelength, amplitude, or speed?
amplitude
what is a magnetic domain
an area where the iron atoms are aligned
blue shift
an increase in the measured frequency of light from an approaching source; the increase is towards the high frequency end of the color spectrum
Thermal Expansion
an increase in the size of a substance in response to an increase in the temperature of the substance
vibration
an oscillation, or repeating back-and-forth motion, about an equilibrium position
How many forces are required for an interaction?
at least two
A new Moon appears in the sky just before the time of a a. lunar eclipse b. solar eclipse c. both d. neither
b. solar eclipse
Name two kinds of practical "electric pumps."
batteries and automobile alternators (electric generator). These do work to pull negative charges away from positive ones. By chemical disintegration or electromagnetic induction. The different values of energy per charge create potential difference. Van de Graaff is not practical! (single brief surge of voltage)
why does a generator produce alternating current
bc every 1/2 turn of the wire coil it changes from facing the magnet N pole to the S pole, which pulls the wire e- in the opposite direction
why are metals good conductors both of heat and electricity?
bc the atoms have a looser outer e-
When electrons are diffracted by a double slit do they hit the screen in a wave-like way or particle-like way? is the pattern of hits wave-like or particle-like
beams of electrons exhibit interference patterns. Like photons, electrons strike as particles but the pattern of arrival is wavelike
Why do both the Sun and the Moon exert a greater gravitational force on one side of the Earth than the other?
because of the distance between the sun or moon and the earth is different for the near and far sides. The near side will feel a greater pull of gravity than the far side.
Why is there a torque about the Moon's center of mass when the Moon's long axis is not aligned with Earth's gravitational field?
because the Moon's center of gravity is slightly displaced from it's center of mass. So when the Moon's axis is not aligned, the Earth's gravitational field exerts a torque on the Moon to realign the axis.
refraction
bending of sound or any wave caused by difference in wave speeds
What color of light will be transmitted through overlapping cyan and magenta filters?
black
cyan (complementary colors)
blue + green
Why do the same notes plucked on a banjo and on guitar have distinctly different sounds?
both have different amplitude partials when playing the same note, so they have a different quality of sound too
A light signal and a radio signal were emitted simultaneously from Alpha Centauri. The first to reach the Earth would be the a. radio signal b. light signal c. both the same
c. both the same time Electromagnetic waves traveling through free space never change speed
Which of these electromagnetic waves have the longest wavelength?: a. infrared waves b. X-rays c. radio waves d. light waves e. ultraviolet waves
c. radio waves
echo
caused by reflected sound reverberations
cite an example of something charged by friction
charging by friction: rubbing a balloon
which warms more quickly in sunlight, colorless or colored piece of glass?
colored; keeps more of the light
destructive interference
combination of waves where crests of one wave overlap troughs of another resulting in a wave of decreased amplitude (cancellation)
compression
condensed region of medium through which a longitudinal wave travels
what color results when red is subtracted from white light?
cyan
if you look with a magnifying glass at pictures printed in full color in this or toher book youll notice which 3 colors?
cyan, magenta, and yellow
When something is painted red, what color is most absorbed?
cyan, the complementary (opposite) color
Our eyes are not very good at seeing a. color in dim light b. motion at our peripheries c. differences in brightness d. all of the above e. none of the above
d. all of the above
what effect does earth's magnetic field have on the intensity of cosmic rays striking the earth's surface
deflects the suns cosmic rays, protecting us from radiation
low
does a longer string on an instrument make a low pitch or a high pitch
What do the various colors displayed in a flame represent
due to excitation- different atoms in the flame emit color characteristic of their energy-level spacings
Light is the oscillation of
electric and magnetic fields. Discovered by Maxwell.
why are electrons, rather than protons, the principle charge carriers in metal wires
electrons are free to leave their atoms
how does the charge of one electron compare to that of another electron? How does it compare with the charge of a proton
electrons have the same negative (-) charge protons have a positive (+) charge
When you make your household electric payment at the end of the month, are you billed for voltage, current, power, or energy?
energy
if a bat hits a ball with 1000N of force, can the ball exert less than 1000N of force on the bat? more than 1000N?
equal to
electric current
flow of electric charge
Amplitude
for a wave or vibration, the maximum displacement on either side of the equilibrium (midpoint) position
natural frequency
forced vibrations match and create greater amplitude
v = wavelength x frequency
formula for wave speed (velocity)
What is meant by free fall?
free fall is when an object is pulled only by gravity (no friction) and accelerates at 10m/s²
What is the function of fuses or circuit breakers in a circuit
fuses or circuit breakers cut off excessive current to wires to prevent them from overheating and melting
For a planet of uniform density, how would the magnitude of the gravitational field halfway to the center compare with the field at the surface?
g/2m/s^2
excited state
greater energy than the atom's lowest energy state
the unit of frequency is called a
hertz, one vibration per second is 1 hertz
A high-fidelity sound system may have a frequency range that extends up to or beyond 20,000 Hz. What is the purpose of this extended range?
high frequencies are needed to accurately reproduce the quality of sounds
pitch
high frequency results in high____________
How does a high-pitch musical note relate to frequency?
high pitch is how the ear perceives high frequencies
How great is the force of friction compared with your push on a crate that doesn't move on a level floor?
if a pushed crate doesn't move, the friction force is equal to and opposite the push force
If the net force acting on a sliding block is somehow tripled, by how much does the acceleration increase?
if the force triples, the acceleration also triples
If the mass of a sliding block is tripled while a constant net force is applied, by how much does the acceleration decrease?
if the mass triples, the acceleration will be 1/3 the original
What relationship does mass have with inertia?
inertia is proportional to mass
What part of the electromagnetic spectrum is most absorbed by water?
infrared
What is the difference between sound intensity and loudness?
intensity is power per meter squared, whereas loudness is the physiological perception of intensity
calorie
is the amount of heat energy required to raise the temperature of 1 g of water by 1°C; also the amount of heat energy that 1 g of water releases when it cools by 1°C. The Calorie (with a capital C), usually used to indicate the energy content of food, is a kilocalorie.
what is the evidence that white light is a composite of all the colors of the spectrum?
it can be broken down using a glass prism
How does the thickness of paint sprayed on a surface change when the sprayer is held twice as far away?
it is 1/4 the thickness of the closer distance. Inversesquare law (1/22 = 1/4 )
Why are thick wires rather than thin wires usually used to carry large currents?
less resistance
whhy does the sun look redish at sunrise and sunset but not at noon
light passes thru a thick layer of atmosphere which scatter B,G leaving red
incandescence
light that is produced as a result of high temperature has this property
What does a decibel measure?
logarithmic measure of sound intensity
How is the wavelength of light related to its frequency
lower frequency = longer wavelength higher frequency = shorter wavelength
What is the color of visible light of the lowest and highest frequencies
lowest frequency = red highest frequency = violet
white light - green light =
magenta light green light + (red + blue) = white
subtractive primary colors
magenta, yellow, and cyan
what must change in order for electromagnetic induction to occur
magnetic field must change
Which is more fundamental, mass or weight? Which varies with location?
mass is more fundamental than weight. Weight varies with location because gravity can vary (different planet, moon)
pigment
material that selectively absorbs colored light
What exactly is an ampere?
measurement unit for rate of electrical flow. One ampere = 1 coulomb of charge per second. *1 coulomb = 6.25 X 10^18 e-
sound is a
mechanical wave which needs a medium to vibrate through (solid, liquid, gas, or plasma)
what are three ways in which voltage can be induced in a wire
moving the magnet over the wire moving the wire over the magnet changing the magnet
can you physically touch another person without that person touching you with the same magnitude of force?
no you both would be touching each other with the same force
can an action force exist without a reaction force?
no, a force is always part of a mutual action that involves another force
crest
one of the places in a wave where the wave is highest or the disturbance is greatest
trough
one of the places where the wave is lowest, or the disturbance is greatest, in the opposite direction from a crest
what two kinds of rotational motion are exhibited by electrons in an atoms
orbits the nucleus spins on its axis
What besides the amount of light affects the size of the pupil of the eye?
our emotions! dilate with pleasure, contract with aversion.
Are automobile headlights wired in parallel or in series? What is your evidence?
parallel if both turn on at same time
What is meant by the fundamental frequency of a musical note?
partial tone at the lowest frequency
line spectrum
pattern of distinct lines of color with each line corresponding to a frequency of light
of a vibration br wave is the time for one complete vibration
period
a wave is a
periodic wiggle in both space and time. A wave extends from one place to another.
a sine curve is a
pictorial representation of a wave produced by simple harmonic motion
frequency corresponds to
pitch, high pitched sound from a piccolo has a high frequency; low pitched sound of a fog horn has a low frequency.
what is meant by the superposition principle?
place two or more waves in the same place at the same time. The result will be one wave that is the sum of their combined effects
antinode(s)
position(s) on a standing wave where the largest amplitude(s) occur(s)
what is a positive ion? negative ion?
positive ion-- an atom that lost an e- negative ion-- an than that gained an e-
For the projection of light, the primary colors are RGB. What about light we see by reflection from opaque surfaces?
primary colors are CMY
The electromagnetic spectrum consists of 7 things
radio waves microwaves infrared light ultraviolet rays X-rays gamma ray
What color light is transmitted through a piece of red glass?
red
magenta (complementary colors)
red + blue
yellow (complementary colors)
red + green
what part of the elctromagnetic spectrum is most absorbed by water?
red light
additive primary colors
red, green, and blue
What part of the visible electromagnetic spectrum is most absorbed by water?
red. Thus the complementary color of red, cyan, is visible
what is the relationship between the frequency of light and its color?
red= lowest frequency blue and violet= highes frequency
A mirage is the result of atmospheric _______.
refraction
rarefaction
region of reduced pressure in medium in which a longitudinal travels
What determines the musical quality of a note?
relative intensities of the various partials
Reverberation
repeated echoes of sound
resonance
response of a body when forcied frequency matches its own
What colors of ink do color ink-jet printers use to produce a full range of colors? Do the colors form by color addition or by color subtraction?
secondary colors, by color subtraction
What did Fourier discover about complex periodic wave patterns?
signals can be disassembled into a sum of simple sine waves
what is the basic similarity between a generator and elecric motor? what is the basic difference between them
similarity-- both a motor and generator have coils of wire turning between 2 magnets difference-- a generator converts motion into electricity a motor converts electricity into motion
if we double the frequency of a vibrating medium, what happens to the period of the wave?
since the period is inversely proportional to the frequency, the period will be one-half its original value if its frequency is doubled while keeping wave velocity constant.
As the frequency of a wave of constant speed is increased, does the wavelength increase or decrease
since there is an inverse relationship between frequeny and wavelength,as the frequency increases the wavelength must decrease V=f~; solving for ~ we get ~= v/f
of these sources of blue light: TV screen, the sky, lakes, which are due to scattering?
sky and lakes
which interact more with high frequncy light, small or large particles?
small
Which type of bell interacts more with high-pitched sounds?
small bells
Which particles interact more with high-frequency light?
small particles
voltage source
something that provides a potential difference (electric pump)
scattering
sound or light is absorbed and reemitted in all directions
infrasonic
sound pitch too low to be heard by the human ear (below 20 Hz)
ultrasonic
sound too high to be heard by the human ear
steel
sound travels 15 times faster than in air in ______________
water
sound travels faster in __________________________ than in air
warm air
sound travels faster in___________________________than in cold air.
wind conditions, temperature and humidity
speed of sound depends on________________________________
330m/s
speed of sound in dry air
one millionth
speed of sound is ______________________________the speed of light
spectrum
spread of colors
Thermal Contact
state of two or more objects or substances in contact such that heat can flow from one to the other
Why do orchestras generally have a greater number of stringed instruments than wind instruments?
stringed instruments produce sounds with lower efficiency than wind instruments
acoustics
study of sound properties
Internal Energy
sum of the kinetic and potential energies of all particles in the system
If the resistance of a circuit remains constant while the voltage across the circuit decreases to half its former value, what change occurs in the current?
t is cut in half.
ultrasonic
term applied to sound frequencies above 20,000 Hz, the normal upper limit of human hearing
infrasonic
term applied to sound pitch too low to be heard by the human ear, that is, below 20 Hz
pitch
term that refers to how high or low sound frequencies appear to be
What is the acceleration of a falling object that has reached its terminal velocity?
terminal velocity=constant velocity so acceleration=0m/s²
If electrons flow very slowly through a circuit, why does it not take a noticeably long time for a lamp to glow when you turn on a distant switch?
that is circuit?
in a circuit of two lamps in a parallel, if there is a voltage of 6V across one lamp, what is the voltage across another lamp
the V drop across lamps in parallel is the same, 6V
bow wave
the V-shaped disturbance created by an object moving across a liquid sufarce at a speed greater than the wave speed
bow wave
the V-shaped wave produced by an object moving on a liquid surface faster than the wave speed
f
the abbreviation for frequency
λ
the abbreviation for wavelength
Specific Heat Capacity
the amount of heat energy required to raise the temperature of one gram of substance by one degree Celsius
Doppler Effect
the apparent change in the frequency of a wave due to the motion of the source and/or the observer
simple harmonic motion
the back-and-forth vibratory motion of a swinging pendulum
consider hitting a baseball with a bat. if we call the force the bat exerts against the ball the action force, identify the reaction force.
the bat hitting the baseball
How does the sum of the currents through the branches of a simple parallel circuit compare with the current that flows through the voltage source
the branches of a parallel circuit equal the current through the battery (V source)
if the world pulls you downward against you chair, what is the reaction force?
the chair pushing up against you
interference
the combination of two or more waves that results in a single wave
shock wave
the cone-shaped disturbance created by an object moving at supersonic speed through a fluid
What does it mean to say that a certain current is 60 Hz?
the current alternates back and forth at a frequency of 60 cycles per second.
what is destructive interference?
the decreased in wave amplitude caused by the superposition of waves. This occurs when the crest of on wave is in the same space as the trough of another wave
the wavelength of a transverse wave is the distance between successive crest. what is the wavelength of a longitudinal wave
the distance between two compressions
amplitude
the distance from the midpoint to the maximum (crest) of a wave, or equivalently from the midpoint to the minimum (trough)
wavelength
the distance from the top of the crest of a wave to the top of the following crest, or equivalently, the distance between successive identical parts of the wave
where is the energy stored in a capacitor
the energy in a capacitor is stored on charged metal plates
When you walk on a floor, what pushes you along?
the floor
when a cannon is fired, are the forces on the cannonball and on the cannon equal in magnitude? are the accelerations of the two equal?
the forces are equal. though the acceleration is not.
sonic boom
the loud sound resulting from the incidence of a shock wave
What part of an atom is positively charged and what part is negatively charged?
the molecules of an atom (with p+) have a + charge the electrons in orbit have a negative charge
frequency
the number of events (cycles, vibrations, oscillations, etc) per unit of time
What is meant by the period of a pendulum?
the period of a pendulum is the time required for the bob to swing out and back once
5 seconds
the period of a skyscraper that sways back and forth at a frequency of about 0.2 Hz
How does the Doppler effect aid police in detecting speeding motorists?
the radar unit sends out waves of invisible light at a specific frequency. some of the waves bounce off the vehicle and return back to the officer. The faster your relative motion, the larger the frequency shift. the unit then calculates your speed and displays it on a screen.
Electric Power
the rate electrical energy is converted into another form such as mechanical, heat or light
Only a small percentage of the electric energy fed into a common lightbulb is transformed into light. What happens to the remaining energy?
the remaining is emitted as heat
superconductivity
the resistance of some materials becomes zero at very low temperatures
sonic boom
the sharp crack heard when the shock wave that sweeps behind a supersonic aircraft reaches the listener
for each degree rise in temperature about 0 degrees Celsius,
the speed of sound in air increases by 0.6 meters per second
period
the time required for a pendulum to make one to-and-fro swing; also, the time it takes for one complete cycle or wave oscillation to occur
forced vibration
the vibration of an object that is made to vibrate by another vibrating object that is nearby
in what direction are the vibrations relative to the direction of wave travel in a longitudinal wave
the vibrations are in the direction of propagation
in a transverse wave, in which direction does the medium vibrate when compared to the direction that the wave is moving?
the wave vibrates at right angles (90degrees) to the direction of wave propagation.
Sine Curve
the waveform traced by simple harmonic motion, which can be made visible on a moving conveyor belt by a pendulum swinging at right angles above the moving belt
How do frequency and period relate to each other
they are inversely proportional to each other. Frequency = 1/T where T represents the period
what occurs when the outer electrons that buzz about the atomic nucleus encounter electromagnetic waves?
they jump to a higher orbit
what is the evidence for a varitey of droplet sizes in a cloud?
they scatter R,G,B
what is the primary purpose of a lighting rod
to give lighting a safe path to reach the ground
why are R,G,B called the additive primary colors?
together they = white
low frequency sounds
travel farther in air than higher frequencies
True or false: when a net force is exerted on a system, the system will accelerate, but when an applied force and its reaction are within a system, the system as a wholes does not accelerate.
true
complementary colors
two colors added together to produce white
Superposition
two identical transverse waves in phase produce a wave of increased amplitude
destroy each other
two identical transverse waves out of phase___________________________
the length of the pendulum and the acceleration of gravity
two things that determine the period of the pendulum
deconstructive interference
two waves combine to make a smaller amplitude wave
In what region of the electromagnetic spectrum is the resonant frequency of electrons in glass
ultraviolet
light is a
vibration of electric and magnetic fields
will water flow more easily through a wide pipe or a narrow pipe? will current flow more easily through a thick or thin wire?
water flows more easily-- wide pipe electric current flows more easily-- thick wire
Calculate the speed of waves in a puddle that are 0.15 m apart and made by tapping the water surface twice each second.
wave speed = wavelength x frequency = 0.15 m x 2 Hz = 0.3 ms/s
What relationship does mass have with weight?
weight is proportional to mass
how does the wetness affect the resistance of your body
wetness decreases the resistance of your body I = VR thus increasing the current
when can two kicks on a soccer ball produce a net force of zero on the ball?
when they are both simultaneously kicking the ball
from where do the electrons originate that produce an electric shock when you touch a charge conductor
when you touched a pie tin and got shocked, the e- came from the pie tin atoms
state newtons thir law of motion
whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first object
rarefaction
where the particles are spread apart
magenta + yellow + cyan =
white light
Yellow light + blue light =
white light yellow is red + green red + green + blue = white
a vibration is a
wiggle in time
What is the color of the peak frequency of solar radiation when it is plotted versus wavelength?
yellow-green. Check out the radiation curve of sunlight
Does a baseball bat slow down when it hits a ball? Defend your answer.
yes The ball's momentum changes when it's hit. To impart this momentum change to the ball, the bat is going to lose momentum, and when it does so, it slows down.
Do tides occur in the molten interior of Earth for the same reason that tides occur in the oceans?
yes, due to the difference in gravitational force across the core
If you push a crate horizontally with 100 N across a 10-m factory floor and the friction between the crate and the floor is a steady 70 N, how much kinetic energy does the crate gain?
ΔKE = work done = (100 N - 70 N)(10 m) = (30 N)(10 m) = 300 Nm = 300 J.
If a car moves with a constant velocity, does it also move with a constant speed?
Yes, because constant velocity requires constant speed in the same direction.
What would the magnitude of the gravitational field be anywhere inside a hollow, spherical planet?
Zero N/kg
Rarefaction
a part in a longitudinal wave where the particles are spread apart
vibration
a wiggle in time
Since white light is all the colors added together, what is black?
absence of light
name the two kinds of practical "electrical pumps"
batteries and generators
Does a battery produce ac or dc? Does the generator at a power station produce dc or ac
battery-- dc generator-- ac
Why are all tides greatest at the time of a full moon or new moon?
because the pull of the Sun and the Moon work together.
identify the force that propels a rocket
cannonballs at the bottom of the rocket
How does the highest pitch one can hear vary with age?
it decreases
What happens to light when it falls upon a material that has a natural frequency equal to the frequency of the light?
it is absorbed. At resonant frequencies at which amplitudes of oscillation are large, light is absorbed.
What happens to light when it falls upon a material that has a natural frequency above or below the frequency of the light?
it is reemitted.
what is constructive interference?
it is the increase in wave amplitude caused by the superposition of waves. The occurs when the crest and trough of one wave is in the same space as the crest and trough of another wave.
What does it mean to say that one wave is out of phase what another?
it means that their crests and trough do not occur at the same place at the same time. This results in destructive interference. If they are 180degrees out of phase, complete destructive interference occurs.
Newton viewed the curving of the path of a planet as being caused by a force acting upon the planet. How did Einstein view the curving of the path of a planet?
its path along the curved space (due to gravity) around an object instead of gravitational attraction as Newton saw it.
how does a helicopter get it's lifting force
its wings
what happens to light when it falls upon a material that has a natural fruquency euqal to the frequency of light?
keep the light
distinguish between monochromatic light and coherent light
monochromatic- consist of single frequency waves but waves out of phase Coherent- beam of photons having the same frequency, phase and direction
what produces a magnetic field
moving electric field (moving e-)
100 per second
the frequency of a 100-Hz wave
the speed of sound depends on
the wind conditions, temperature and humidity. It does not depend on the loudness or the frequency of the sound
beats
useful for tuning instruments
When a glass glows discrete colors are emitted. when a solid glows the colors are smudged. why?
when the atoms are closely packed the electrons of outer orbits make transitions not only within energy levels of "parent atom but also between neighboring atoms so they bounce over larger dimensions
compression
where the particles are close together
For each of the following interactions, identify action and reaction forces. (a) A hammer hits a nail. (b) Earth gravity pulls down on a book. (c) A helicopter blade pushes air downward.
(a) Action; hammer hits nail. Reaction; nail hits hammer. (b) Action; Earth pulls down on you. Reaction; you pull up on the Earth. (c) Action; helicopter blade pushes air downward. Reaction; air pushes helicopter blade upward. (In these examples, action and reaction may be reversed—which is called which doesn't matter.)
Identify the action-reaction pairs of forces for the following situations: (a) You step off a curb. (b) You pat your tutor on the back. (c) A wave hits a rocky shore.
(a) Action; your foot pushes curb. Reaction; the curb pushes your foot. (b) Action; your hand pats tutor's back. Reaction; your tutor's back "pats" your hand. (c) Action; waves exert forces on rocky shore. Reaction; rocky shore exerts forces on waves.
7. What is meant by conservation of charge?
-electric charge can neither be created nor destroyed
What are the three ways in which voltage can be induced in a wire?
1~ by moving a loop of wire near a magnet 2~ by moving a magnet near a loop of wire 3~ by changing the current in a nearby loop of wire
D
22) If a compass is moved from the northern hemisphere to the southern hemisphere, its magnetic needle will change direction A) by 180 degrees. B) depending on where the measurement is taken. C) by 90 degrees. D) hardly at all. E) none of these
C
4) A positive ion has more A) electrons than neutrons. B) electrons than protons. C) protons than electrons. D) protons than neutrons. E) neutrons than protons.
Node
A point of zero amplitude on a standing wave
What would the magnitude of the gravitational field be anywhere inside a hollow, spherical planet? A) Zero N/kg B) A quarter of the surface value C) Half the surface value D) The same as the surface value
A) Zero N/kg
What fraction of the light shining straight at a piece of clear glass is reflected from the first surface?
About 4%
What is the effect of air resistance on the acceleration of falling objects?
Air resistance decreases the acceleration of falling objects.
How does an absorption spectrum differ in appearance from an emission spectrum?
An emission spectrum consists of bright lines against a dark background, whereas an absorption spectrum consists of dark lines against a bright rainbow background.
What exactly is meant by a "freely falling" object?
An object in free fall falls under gravity alone with no friction.
What produces an electromagnetic wave?
An oscillating or accelerating electric charge. "The vibrating electric and magnetic fields regenerate each other to make up an *electromagnetic wave* which emanates from the vibrating charge."
Radioactivity in the world is something to become frantic about. relatively new. as old as the world itself.
As old as the world itself
What is a gravitational field, and how can its strength be measured? A) It is a force field in empty space with direction and magnitude equal to the inverse square of the mass of a test mass. B) It is a force field on any body with mass, its strength is the force per unit mass on a test mass. C) It is a force field with direction and magnitude at every point in space. It's strength is the force on a test mass. D) It is a force field on a body with mass, with direction and magnitude equal to the inverse square of the distance to a test mass.
B) It is a force field on any body with mass, its strength is the force per unit mass on a test mass.
A fireman pushes on a closed door. What force makes a reaction pair with the force exerted by the fireman onto the door? A) The force exerted on the ground by the fireman. B) The force exerted on the fireman by the door. C) The force exerted on the fireman by the ground (due to friction).
B) The force exerted on the fireman by the door. Due to Newton's 3rd law, these two forces are equal and opposite.
Do tides depend more on the strength of gravitational pull or on the difference in strengths? Explain. A) Tides depend on both the strength and the difference equally B) Tides depend only on the difference. C) Tides depend weakly on the difference and strongly on the strength D) Tides depend only on the strength
B) Tides depend only on the difference.
22) Which interacts more with light of relatively high frequencies? A) large particles B) small particles C) both the same
B) small particles
15) Colors seen on the cover of our physics book result from color A) addition. B) subtraction. C) either of these D) neither of these
B) subtraction.
Which of the following are creatures that are known to harbor tiny magnets within their bodies?
Bacteria, pigeons, bees, wasps, monarch butterflies, and sea turtle
Name two kinds of practical "electric pumps."
Batteries and automobile alternators
Which has the higher frequency: red or blue light? Which has the greater energy per photon: red or blue light?
Blue light, blue light. "A photon in a beam of red light carries an amount of energy corresponding to its frequency." Low frequency = low energy. "A photon of twice the frequency has twice the energy; found in UV part of spectrum, blue." Higher frequency = hi energy.
what is meant by a blue shift and a red shift for light
Blue shift for light indicates an increase in frequency and tells you that the objects are approaching on another. Red shift is a decrease in frequency and indicates that the objects are moving apart
Which has the higher frequency, red light or blue light?
Blue. The lowest frequency light we can detect appears to most people as the color red, and the highest frequency as violet.
Applying E = hf to photon emission from an atom, the symbol E represents the energy difference between atomic energy levels producing the photon. of the emitted photon. both of these neither of these
Both of these
24) A whitish sky is evidence that the atmosphere contains A) predominantly small particles. B) predominantly large particles. C) a mixture of particle sizes. D) water vapor. E) pollutants.
C) a mixture of particle sizes.
6) The solar radiation curve is A) a dent in the otherwise spherical sun. B) the path taken by the sun as it travels around the Earth. C) a plot of brightness of sunlight versus its frequency. D) a plot of the colors of sunlight versus their frequencies. E) a plot of light intensity versus distance from the sun.
C) a plot of brightness of sunlight versus its frequency.
Which has the greater mass? A) a king-size pillow B) neither - both have the same C) an automobile battery
C) an automobile battery
29) A variety of sunset colors is evidence for a variety of A) elements in the sun. B) apparent atmospheric thicknesses. C) atmospheric particles. D) atmospheric temperatures. E) primary colors.
C) atmospheric particles.
A person pushes a large crate across the room to the right. Friction acts on the crate as well as on the person's feet. If the crate accelerates to the right, the net force on the system made up of the person and the crate is A) directed to the left. B) zero. C) directed to the right.
C) directed to the right. The net force on this system is due to the force of friction acting on the person (to the right) and on the crate (to the left). Since the person is pushing harder than the force of friction on the crate, and since the crate must be pushing on the person with the same force as the person is pushing on the crate, the force of friction exerted on the person due to friction must be greater than the force of friction exerted on the crate.
36) If sunlight were green instead of white, the most comfortable color to wear on a hot day would be A) magenta. B) yellow. C) green. D) blue. E) violet.
C) green.
39) Distant snow covered hills appear yellowish because that is the color of the A) atmosphere between the observer and the hills. B) selectively reflected light that reaches a distant observer. C) reflected light that survives scattering. D) sky that is reflected off the hills.
C) reflected light that survives scattering.
3) The color of an opaque object is the same as the light that is A) transmitted. B) absorbed. C) reflected. D) all of these E) none of these
C) reflected.
35) A blue object will appear black when illuminated with A) blue light. B) cyan light. C) yellow light. D) magenta light. E) none of these
C) yellow light.
How does a lifetime of a typical CFL bulb, incandescent, and LED compare
CFLs- more efficient than incandescent- 4x as much for same power input and 10x the lifetime LED- more efficient than both and have lifetime 100x longer than incandescent
Which of the following isotopes is radioactive? Carbon-14 Carbon-12 both of these neither of these
Carbon-14
What did Newton discover about gravity? A) The Newtonian Synthesis B) The Law of Universal Gravitation C) The equation for the force of gravity D) All of the above
D) All of the above
27) Red sunsets are due to lower frequencies of light that A) are scattered from larger particles in the air. B) are refracted from larger particles in the air. C) are reflected by clouds and relatively large particles in the air. D) survive being scattered in the air. E) appear reddish orange to the eye.
D) survive being scattered in the air.
Why does the color of sunsets vary from day to day?
Different particles in the air each day scatter and absorb different wavelengths of light, thus giving the sky many different colors.
At what speed do electrons in a battery driven automotive circuit travel along a wire? At what speed does the electric field propagate along a wire?
Electrons move at 0.01 cm/s. The electric field propagates at nearly the speed of light.
If the forces that act on a cannonball and the recoiling cannon from which it is fired are equal in magnitude, why do the cannonball and cannon have very different accelerations?
Equal forces on unequal masses produce unequal accelerations, in accord with Newton's second law.
How can a hydrogen atom, which has only one electron, have so many spectral lines?
Every transition from one of those levels to another is a spectral line. The spectral lines correspond to the electron transitions between atomic levels, characteristic of each element. The spectral lines represent the wavelengths of light given off when an electron changes energy levels. Even a simple system with two particles (electron and nucleus) has an infinite number of energy levels available to it.
What is the net force that acts on a 10N falling object when it encounters 4N of air resistance? 10N of air resistance?
Fnet=10N-4N=6N down Fnet=10N-10N=0N
Does heating a metal wire increase or decrease its electrical resistance? Why?
Heated metal wires increase resistance because atoms at higher temperatures jostle into the way of moving electrons.
What vibration frequency does a high-pitched sound have?
High frequency
How is the fact that an electromagnetic wave in space never slows down consistent with the law of conservation of energy?
If light slowed down, its energy would decrease, thereby violating the law of conservation of energy. "There is only one speed for which electric and magnetic fields remain in perfect balance... carrying energy forward without loss or gain." "Energy would be lost and none would be transported form one place to another. So light cannot travel slower than it does."
Why can a tuning fork or bell be set into resonance, while a tissue paper cannot?
In order for something to resonate, it needs a force to pull it back to its starting position and enough energy to keep it vibrating. Tissue paper is too limp to resonate.
Which is more fundamental, mass or weight? Which varies with location?
In the absence of acceleration, mass and weight are directly proportional to each other. If the mass of anobject is doubled, its weight is also doubled; if the mass is halved, the weight is halved. Because of this, massand weight are often interchanged. However, mass is more fundamental than weight; it is a fundamentalquantity that completely escapes the notice of most people. Weight varies with location.
How does incident light that falls on an object affect the motion of electrons in the atoms of the object?
Incident light makes the electrons oscillate. The electrons then emit light or absorb the light and convert it to heat.
Fill in the blanks, Newton's first law is often called the law of ________. Newton's second law is the law of ________ and Newton's third law is the law of ________ and ________.
Inertia; acceleration; action; reaction
Why are infrared waves often called heat waves?
Infrared light vibrates entire atoms and molecules, and this vibration increases the temperature of the absorbing substance.
What is the fate of the energy in infrared light incident on glass?
Infrared light will make atoms vibrate, thus becoming internal energy and a temperature increase. "Frequencies lower than those of visible light cause entire atoms or molecules to vibrate, increasing internal energy and temp." *heat waves
Where do the electrons come from that produce an electric shock when you touch a charged conductor?
Inside you
Does a single raindrop illuminated by sunlight deflect light of a single color or does it disperse a spectrum of colors? Does it do this by reflection, refraction, or both?
It disperses a spectrum of colors, by both reflection and refraction.
What is the distance fallen for a freely falling object 1 s after being dropped from a rest position? What is the distance for a 4-s drop?
It falls 5 m in 1 s and 80 m in 4 s.
In what sense does the Moon "fall"?
It falls away from the straight path that it would follow if there were no forces acting on it.
What is the gain in speed per second for a freely falling object?
It gains approximately 10 m/s.
What is the function of the round third prong in a modern household electric plug?
It grounds the case to zero potential, by connecting the appliance body directly to ground. Any charge buildup is conducted to the ground.
What is the function of the round third prong in a modern household electric plug?
It grounds the case to zero potential.
What happens to the strength of the gravitational field at the surface of a star that shrinks?
It increases
Does heating a metal wire increase or decrease its electrical resistance? Why?
It increases resistance because atoms at higher temperatures jostle into the way of moving electrons.
How does the thickness of paint sprayed on a surface change when the sprayer is held twice as far away?
It is 1/4 as thick
What is a gravitational field, and how can its strength be measured?
It is a force on any body with mass. its strength is the force per unit mass on a test mass
What property of a diode enables it to convert ac to pulsed dc?
It is a one-way valve that allows electrons to in one direction only.
When an object is thrown upward, how much speed does it lose each second (ignoring air resistance)?
It loses 10 m/s of speed each second until it reaches the high point, then it gains 10 m/s each second.
If a car is moving at 90 km/h and it rounds a corner, also at 90 km/h, does it maintain a constant speed? A constant velocity?
It maintains a constant speed, but does not maintain a constant velocity.
How does refraction change the apparent depth of a swimming pool?
It makes the pool look shallower - only 3/4 as deep.
What effect does Earth's magnetic field have on the intensity of cosmic rays striking Earth's surface?
It reduces the intensity. Still, "secondary" cosmic rays reach Earth's surface, greatest at magnetic poles, and decreases away from the poles; smallest at equatorial regions. *ex. aurora borealis and australis.
How often is current reversed in the loops of a simple dc electric motor?
It reverses twice each cycle.
How often is current reversed in the loops of a simple dc electric motor?
It reverses twice each cycle. Once every half cycle
In which medium does light travel faster - thin air or dense air? How does this affect the length of daylight hours?
It travels faster in thin air, which makes sunlight curve and extends the length of the day.
A car is raised a certain distance in a service-station lift and therefore has potential energy relative to the floor. If it were raised twice as high, how much more potential energy would it have?
It would have twice the PE because the distance is two times greater.
What will be the kinetic energy of a pile driver ram that starts from rest and undergoes a 10-kJ decrease in potential energy?
Its gain in KE will equal its decrease in PE, 10 kJ.
Why does the sky sometimes appear whitish?
Large particles in the atmosphere scatter longer wavelength light that adds to the blue light to create white light.
About how much of the measured electromagnetic spectrum does light occupy?
Light occupies less than one millionth of one percent (<.000001%) of the measured electromagnetic spectrum.
What is Fermat's principle of least time?
Light takes the quickest path in going from one place to another.
How is the rule for the interaction between magnetic poles similar to the rule for the interaction between electrically charged particles?
Like poles repel, unlike poles attract, and the force is proportional to the inverse square of the distance between two poles.
What vibration frequency does a low-pitched sound have?
Low frequency
Which of the three laws deals with interactions?
Newton's third law, the law of action-reaction
Can sound travel in a vacuum?
No
When you rub your hands together, can you push harder on one hand than the other?
No, for each hand pushes equally on the other in accord with Newton's third law- you cannot push harder on one hand than the other.
Can sound travel through a vacuum? Explain.
No. Sound requires a medium
A nucleon is either a proton or a neutron. neutron or an electron. positron or an electron. proton or an electron.
Proton or a neutron
An excited atom decays to its ground state and emits a photon of green light. If instead the decay is to an intermediate state, then the light emitted could be blue. red. violet. any of the above none of the above
Red
What two kinds of motion do electrons in an atom appear to have?
Revolution and spin
What amount of time do we relate to frequency?
Seconds
Does a battery produce dc or ac? Does the generator at a commercial power station produce dc or ac?
The battery is dc; the generator is ac.
How does the frequency of a radio wave compare to the frequency of the vibrating electrons that produce it?
The frequency of a radio wave is the same as the frequency of the vibrating electrons that produce it
Antinodes
The points in a standing wave where you can hear sound are the _____.
Period
The time in which a vibration is completed. The period of a wave equals the period of the source and is equal to 1/frequency
What is the source of all sounds?
Vibrating objects
Resonance
When a *forced vibration* matches the natural frequency of an object, producing more vibration, sound, or damage.
Is it possible for one sound wave to cancel another? Explain.
Yes, it is destructive interference
As you read this in your chair, how fast are you moving relative to the chair? Relative to the Sun?
You are not moving relative to the chair, but you are moving over 100,000 km/h relative to the Sun.
Where do you weigh more: at the bottom of Death Valley or atop one of the peaks of the Sierra Nevada? Why?
You weigh more in Death Valley because you are closer to the center of Earth
why will dropping an iron magnet on a hard floor make it a weaker magnet
bc it shakes the iron atoms out of alignment
How does the lifetime of a typical LED compare with the lifetime of an incandescent bulb?
The LED lasts 100 times longer. Compact, efficient, require no filament, and have no mercury. Diodes convert ac to dc in electric circuits. LED is a reverse photocell; an impressed voltage stimulates light emission.
How does the difference in energy between energy levels relate to the energy of the photon that is emitted by a transition between those levels?
The energy of the photon is equal to the difference in energy between the energy levels. E~f Electrons dropping from hi to low energy levels in an excited atom emit with each jump a throbbing pulse of electromagnetic radiation (photon) with frequency related to the energy transition of the jump. E=hf
A boxer can hit a heavy bag with great force. Why can't he hit a piece of tissue paper in midair with the same amount of force?
The mass of the tissue paper is not equal to the mass of the boxer. He can't exert any more force on the tissue paper than the tissue paper can exert on him. The tissue paper has insufficient inertia for a great force.
What are Fraunhofer lines
The spectrum of the sun is not continuous and produces these lines - indicate whether that sun and stars surrounded by atmosphere of cooler gas that absorb some of the light coming from the main body
What does it mean to say an energy state is discrete?
The state has a precise energy. These states are found only at certain energies.
Why is ultraviolet light, but not infrared light, effective in making certain materials fluoresce?
The ultraviolet light photons have higher energy than visible light photons, whereas the infrared have lower energy. Thus, some of the ultraviolet energy can be reemitted as visible color.
Ultraviolet light causes sunburns, whereas visible light, even of greater intensity, does not. Why is this so?
There is more energy associated with each photon of ultraviolet light than with visible light. Visible light mostly just heats the skin, but not enough to cause thermal burns.
Why are fabrics that fluoresce when exposed to ultraviolet light so bright in sunlight?
These clothes (or the detergent used) contain fluorescent dyes that convert the UV light in sunlight into blue visible light, so they reflect more blue light than they otherwise would. The clothes appear whiter and brighter.
How does friction affect the net force on an object?
When surfaces slide or tend to slice over one another, a force of friction acts. When you apply a force to an object, friction usually reduces the net force and the resulting acceleration.
Can a neon atom in a glass tube be excited more than once? Explain.
Yes. The electrons in the atom stay with the same atom as it is excited and de-excited by one collision after another. "Millions of e- vibrate back and forth, smashing...the process occurs and recurs many times, as neon atoms continuously undergo a cycle of excitation and de-excitation. The overall result is transformation of electric energy into radiant energy."
what is a spectroscope and what does it accomplish?
a spectroscope is a tool used for seeing the pattern of electron energy levels in a material
Which has the higher frequency -red or blue light which has the higher energy per photon
blue light has higher frequency and therefore has higher energy
What is the uncertainty principle with respect to momentum and position
can not find both at same time if uncertainties are multiplied together the product must be equal to or greater than Planck's constant divided by 2 ℿ the sharper one of the quantities the less sharp the other note: only applicable to quantum phenomenon
When the ends of an electric conductor are at different electric potentials
charge flows from one end to the other
how does the arrangement of photons in laser differ from photons in incadensent light
common lamp is incoherent so photons of many different frequencies and phases of vibration are emitted in a laser the light is coherent so the photons are all of the same frequency with the same phase of vibration
the source of electrons in a circuit is the
conducting circuit material itself including the voltage source such as the battery
how is the energy of a photon related to its vibrational frequency
directly proportional E∼f
how does the peak frequency of emitted light relate to the temperature of an incandescent source
directly proportional f∼T
what does it mean to say an energy state is discrete
each element has an specific energy states also known as quantum states
State Newton's law of universal gravitation in words. Then do the same with one equation.
every body attracts every other body with a force that, for any two bodies, is directly proportional to the product of their masses and inversely proportional to the square of the distance separating them. F = m1m2/d2
What evidence can you site for the wave nature of light particles
every particle of matter endowed with a wave to guide its travels every particle will produce an inference or diffraction pattern
How does friction affect the net force on an object?
friction force decreases the net force on an object
how does absorption spectra differ in appearance from emission spectra
instead of being continuous- there are dark lines across a rainbow colored backgroud so it is like emission lines in reverse these lines correspond directly to the same elements emission lines
when a hammer exerts a force on a nail, how does this amount of force compare with that of the nail on the hammer?
it is equivalent
photoelectric effect
light capable of ejecting electrons from various metal surfaces -electrons ejected as soon as the light is turned on- no foreplay -conceive light as encountering surface as succession of photon - shows particle light behavior
Did Einsteins photon explanation of photoelectric effect support wave theory or particle theory
particle theory
Does light behave as a wave or particle when interacts with crystal matter in photographic film
particle- image is built by individual photons that drive independently and seem random in their distribution in low light
Electric Power is equal to the
product of current and voltage (electric power = current x voltage)
what is the principle of complementarity
quantum phenomenon exhibit complementary properties appearing either as particles or waves depended on type of experiment conducted experiments designed to examine individual changes in energy and momentum reveal particle like qualities experiments designed to examine spatial distribution of energy reveal wavelike properties
what did planck consider quantized: energy of vibrating atoms or energy of light itself
radiant energy emitted in discrete bundles wrong- Einstein: quantum properties to light itself and radiation as hail of particles
Ohm's Law
relationship between voltage, current and resistance
How can tell when star is receding or approaching earth
the frequency of approaching light is higher and the frequency of receding light is lower
Why is ultraviolet light and not infrared light effective in making materials fluoresce
the high energy of of high frequency light delivered more energy per photon than lower frequency light which serves to excite the atom
amperes
the number of Coulombs of charge that flow through a circuit per second
electric resistance
the resistance that the conductor offers to the flow of charge and is directly proportional to its length and resistivity but inversely proportional to its cross sectional area
Once the crate is sliding, how hard do you push to keep it moving at constant velocity?
to keep the crate moving at constant velocity the push force is equal to and opposite the friction force
ohms
unit of measurement for electric resistance
Which are more successful in dislodging electrons from a metal surface- photons of violet light and photons of red light? Why? Does this change as the brightness of light changes
violet light because electrons energy depends on frequency of light maximum energy is unaffected by brightness of light
Electrons made to vibrate to and fro at a few hundred thousand hertz emit radio waves. What class of waves is emitted from electron vibrations of a few million billion hertz?
visible light waves would be emitted. Light emission from atoms involve transitions of electrons from higher to lower energy states within atom.
a current-carrying wire has a net electric charge of
zero
2. A force sets an object in motion. When the force is multiplied by the time of its application, we call the quantity impulse and an impulse changes the momentum of that object. What do we call the quantity force multiplied by distance?
-work -energy
Consider just four of the energy levels in a certain atom. How many spectral lines will result from all possible transitions among these levels? Which transition corresponds to the highest-frequency light emitted? To the lowest-frequency light emitted?
6 spectral lines will result. From transitions (n=1↔2), (1↔3), (1↔4), (2↔3), (2↔4), (3↔4). The highest frequency corresponds with the greatest energy difference; transition n=1↔n=4 The lowest frequency corresponding with the smallest energy difference; n=4↔n=3. Higher frequency light (near the blue end of the spectrum) corresponds to high energy levels. Lower frequency light (near the red end of the spectrum) corresponds to lower energy levels. Remember, the energy of the photon is equal to the difference between the energy levels. E~f. The transition from n=1 to n=2 (large gap) would emit the highest frequency light. The transition from n=3 to n=4 (small gap) would emit the lowest frequency light. Given frequencies correspond to a definite wavelength.
What is a spectroscope, and what does it accomplish?
A spectroscope displays the spectrum of light as brightness versus wavelength.
What is the evidence for the claim that iron exists in the relatively cool outer layer of the Sun?
Analysis of the Fraunhofer lines of the Sun's spectrum reveal the chemical composition of the atmosphere. The stellar elements are the same elements existing on Earth. The many absorption lines must have also proved iron exists in this cooler gas outer layer.
What is the Newtonian synthesis? A) His naming of the spectrum ROYGBIV B) The union of terrestrial laws and cosmic laws C) His invention of calculus D) His alchemical work on alloys
B) The union of terrestrial laws and cosmic laws
A lamp filament is made of tungsten. Why do we get a continuous spectrum rather than a tungsten line spectrum when light from an incandescent lamp is viewed with a spectroscope?
Because when tungsten atoms are close-packed in a solid, the otherwise will-defined energy levels of outer electron shells are smeared by mutual interactions among neighboring atoms.The hot filament emits a continuous spectrum, mostly in the infrared, with visible light as the smaller, useful part. (black-body radiation factor?)
Which requires more work: lifting a 50-kg sack a vertical distance of 2 m or lifting a 25-kg sack a vertical distance of 4 m?
Both are the same amount of work because the force x distance is the same for each.
How does the potential energy relative to the nucleus of an electron depend on whether it is in an inner electron shell or an outer electron shell?
Electrons in outer shells have higher potential energy. Similar to energy of a spring door or pile driver. The wider the door is open, higher spring potential energy; higher pile driver lifted, greater gravitational potential energy.
When a gas glows, discrete colors are emitted. When a solid glows, the colors are smudged. Why?
Emitting electrons interact with nearby neighboring atoms in a solid. In a gas, there are few nearby atoms. Think of the clear frequency of a single ringing bell, vs the smudged sound of a crowded box of bells.
What are Fraunhofer lines?
Fraunhofer lines are the absorption spectrum of the outer solar atmosphere viewed against the continuous spectrum of the Sun.
How great is the force of friction compared with your push on a crate that doesn't move on a level floor?
If an object is to move at a constant velocity, a force equal to the opposing force of friction must be applied so that the two forces exactly cancel each other. No friction exists on a crate that sits at rest on a level floor. But, if you push the crate horizontally, you'll disturb the contact surfaces and friction is produced. If the crate is still at rest, then the friction that opposes motion is just enough to cancel your push.
In a neon tube, what occurs immediately after an atom is excited?
It de-excites and emits light. Electrons are boiled off electrodes at tube ends, jostling at high speeds by AC voltage; smashing boosts orbital e- into higher energy levels. The energy is radiated as red light (neon) and e- fall back to stable orbits (ground state).
Which puts out the greater percentage of its energy as visible light: an incandescent lamp or a mercury-vapor lamp? How is the remaining non-visible light energy emitted?
Mercury-vapor lamp; incandescent lights emit more in the infrared. Mercury emits blues and violets; Sodium emits orange-yellow.
What is the Newtonian synthesis?
Newtonian synthesis was the union of terrestrial and cosmic laws brought about by Newton's discovery that Gravity is universal..
Cite an example in which a force is exerted on an object without doing work on the object.
No work is done in pushing on a stationary wall
Distinguish between fluorescence and phosphorescence.
Phosphorescence has a longer time delay between excitation and emission. Fluorescence, UV light excites atoms, which emit visible light when de-excited. (detergents, paints, crayons.) Phosphorescence, electrons are boosted then become "stuck", delay before de-excitation.
Distinguish between the primary and secondary excitation processes that occur in a fluorescent lamp.
Primary excitation is when electrons collide with and excite mercury gas. Secondary excitation is when ultraviolet light from the mercury excites a phosphor to emit visible light.
distinguish between the primary and secondary excitation processes that occur in a fluorescent lamp
Primary- tube of neon- electrons forced to vibrate by ac voltage- mercury atoms excited by impact of high-speed electrons- emits light in ultraviolet region Secondary- ultraviolet light strikes phosphors which are excited by absorption and emit a multitude of low-frequency photons that combine to produce white light
When you push against a wall with your fingers, they bend because they experience a force. Identify this force.
Reaction force - wall pushes back on your fingers.
Distinguish between coherent light and sunlight.
Sunlight has a wide range of frequencies, wavelengths, and phases, whereas coherent light has one wavelength, one frequency, and one phase. A beam of photons (laser) have same frequency, phase and direction, identical copies of each other. Spreads and weakens very little.
