MBU Physics Exam
Which of the following can cause a charged particle to accelerate?
(A) and (B) An electric field A gravitational field
A net force of 8 N is applied to a 2 kg object. The object's acceleration is
4 m/s2
SI Unit of Current
Ampere
One way radio waves do not differ from visible light is that
Radio waves travel at the same speed as visible light
Cities have to use water towers to supply water because
Water pressure at the bottom of the tower is much higher than at the top
For an appliance to receive and consume electric power,
a current must flow through it across a voltage decrease
Photons contain mass.
f
The photoelectric effect is what makes X-ray imaging possible because
it involves electromagnetic radiation knocking an electron all the way out of an atom
A projectile is thrown directly upward and caught again. At the top of its path
its vertical velocity is zero
Microwaves have
lower frequencies than visible light
A comet's tail is evidence that electromagnetic radiation has momentum.
t
A kilogram of cotton balls has the same amount of mass as a kilogram of lead.
true
You are flying on an airplane and you notice that a ball of aluminum foil from lunch starts to roll to the left. From the motion of the foil ball you can conclude that the plane is
turning toward the right.
You and a friend are spending a weekend at a carnival. You get bored and begin to make electrostatics measurements. It turns out that you have a charge of +3 Coulombs and your friend a charge of -5 Coulombs. What is the net electric charge?
-2 Coulombs
If a total 5.0 C electrical charge is passed through a section of wire during a 10 second interval what is the current in this area?
0.5 A
The speed of light is about
299 million meters per second
If the current in a circuit is 4.0 A and the resistance is 2.0 Ω what is the power consumed by the circuit?
32 W
A heat engine produces 100 J of energy but dumps 60 J of that energy into the environment. How efficient is this heat engine?
40%
If A = (3 m, 4 m) and B = (7 m, 1 m), find A + B.
A + B = (10 m, 5 m)
Who originally named electric charges as positive and negative?
Benjamin Franklin
Suppose you are driving your car down the highway at constant velocity. Which of the following are true?
Both the car's kinetic energy and momentum are constant.
The SI unit for frequency
Hertz
Electricity and magnetism are different because
There are no magnetic monopoles
The food energy we intake can be converted into work.
True
The reason for using a harmonic oscillator as a clock's time-keeper is so that the clock will keep accurate time even if the
amplitude of the time-keeper's oscillation changes
Which of the following does not make a good thermometer?
hands
The SI units of acceleration are
m/s2
Electrons are
much lighter than protons
While current is flowing the electric field points in the direction opposite of the flow of electrons.
t
Impulse and momentum have the exact same units.
true
1. You are working late in the physics lab, where you measure the period of a pendulum to be 0.8 s. You fall asleep and have a dream that you are on a planet whose gravitational strength is 4 times that of the earth. If your dream is to be physically accurate, the period of the pendulum in your dream must be
0.4 s
You are swinging a tin can around your head in a perfectly horizontal circle and its acceleration is 32 m/s2. If its speed is 4 m/s what is the value of the radius of its circular path?
0.5 m
The amount of work it takes to move a 1 kg object 1 m upwards is approximately:
10 J
Atmospheric pressure is about 100000 Pa. At what depth in water does this pressure double?
10 m
Suppose your speed increases by a factor of 4. By what factor does your kinetic energy increase?
16
A gymnast jumps upward with an initial speed of 10 m/s. She is in the air for a total time of
2 seconds
What is the momentum of a 1000 kg truck traveling at 20 m/s?
20,000 kg*m/s
A power line carries current 10 A and has resistance 2.0 Ohm's . What is the voltage drop across the line?
200 V
Assume you have an adjustable volume container that starts out with a pressure of 100,000 Pa, a volume of 1 m3, and temperature of 300 K. If the temperature and number of particles in the container stays the same, what is the new pressure in the container if the volume is reduced to 0.5 m3?
200,000 Pa
The onset of turbulent flow happens for a Reynolds number of about
2000
You are a deep sea diver and are carrying out pressure tests on your air tanks, which is required by inspection rules. A gas cylinder is filled with a gas at a temperature of 300 K and pressure 200000 Pa. The temperature of the gas is then raised to 400 K. Assuming the volume and number of particles stay the same what is the new pressure?
266667 Pa
A car stereo draws 24 A of current at voltage 12 V. What power does it use?
288 W
"The entropy of an isolated system never decreases." Which Law of Thermodynamics is this?
2nd
You work in a clock shop and are dealing with an irate customer whose clock you are restoring. They notice that the period of the pendulum in their clock is 2 s and they want to double it. So they insist that you replace the pendulum with one of the same dimensions but just heavier. So you do this. When you get the clock repaired, you and the customer check out the clock's period and find it to be
2s
The speed of light is roughly 300,000,000 m/s. A radio station has frequency 100 megahertz. What is the station's wavelength?
3.0 meters
Which of the following is a nonconservative force:
36,000 J
The maximum height above the ground for a the gymnast jumping straight upward with an initial speed of 10 m/s is
5
The maximum height above the ground for a the gymnast jumping straight upward with an initial speed of 10 m/s is
5 m
A car starts from rest and accelerates at 4 m/s2. How much time will it take the car to reach a speed of 20 m/s?
5 s
A 3.0-V battery is used to power a flashlight. If the current in the circuit is 0.6 A, what is the resistance in the bulb?
5.0 Ohms
What is the frequency of a vibration with period 0.02 second?
50 Hertz
If a 50 N force is applied to an object for 10 s the impulse imparted to the object is:
500 kg*m/s
If you wanted to take a steel bar with an initial length of 1.5 m and expand it to 1.51 m just by increasing the temperature what change in temperature would be necessary to accomplish this task? (Steel α = 12×10-6 1/K)
555.6 K
An 800 kg car moving at 4 m/sec to the right strikes a 400 kg car moving to the left. If the cars stick together and stop moving right after the collision, what was the velocity of the 400 kg car?
8 m/sec to the left
Light travels at about 300 million meters per second, and the Sun is about 150 million kilometers from the Earth. How long does it take light from the Sun to reach Earth?
8 minutes
If the voltage drop in a circuit is 4.0 V and the resistance in circuit is 2.0 Ω what is the total power consumed by this circuit?
8.0 W
You are bored during the summertime when school is not in session and you decide to do an experiment where you compare the properties of water and air. If the density of air is 1.25 kg/m3 and the density of water is 1000 kg/m3 , what volume of air weighs the same as 1 liter of water?
800 liters
The radius of a pipe is tripled while the pressure difference across the pipe remains the same. The volume flow rate of the pipe increases by a factor of
81
Most commercial airliners have static dissipaters on their wingtips. These sharp metal spikes extend from the end of each metal wing and point toward the rear of the plane. Suppose a plane had just flown through a negatively charged cloud and acquired a large negative charge. It is now flying through neutral air. Which of the following should you expect to happen near the static dissipaters?
A corona discharge at the dissipater tips will spray negative charge into the air
What does "AM" stand for?
Amplitude Modulation
You go through a loop in a roller coaster at constant speed. Where is your apparent weight a minimum?
At the top
Electromagnetic waves behave like:
Both A and B Particles Waves
Which of the following is a real (not fictitious) force:
Centripital
SI unit of charge
Coulomb
Which of the following quantities is not conserved?
Entropy
Work and energy are not related at all.
False
Your apparent weight is equal to your weight
In an elevator not accelerating.
Assume two bodies collide and stick together. This type of collision is known as:
Inelastic
Copper is a metal that can behave like a magnet because
It is a conductor and can support electric current
The SI unit for energy is:
Joules
You decide to take your younger brother to the park for a fun afternoon. You notice that one ride is basically a seat attached to an old car spring. When a person sits on it, the spring vibrates rapidly but when in a car the spring vibrates much more slowly. This is because
Larger masses on a spring give lower frequencies
Compton scattered a photon by impacting it with an electron. Through this experiment Compton proved that photons have:
Momentum
Suppose you are driving your car down the highway and speeding up. Which of the following are true?
Neither the car's kinetic energy nor momentum are constant.
SI units of force
Newton
Water wave A has a larger wavelength than water wave B. Which wave travels faster?
Not enough information is given to determine
Neglecting air resistance what is the general shape of a projectile's trajectory (assume there is some horizontal motion)?
Parabola
Suppose you are driving north and suddenly hit your brakes to avoid a dog in the road. As you come to a stop your acceleration is directed
South
1. What bridge collapse in 1940 was due to a resonant energy transfer?
Tacoma Narrows Bridge
Why can't you float one permanent magnet directly above another permanent magnet indefinitely by turning their north poles toward one another?
That arrangement is unstable-the upper magnet will fall to the side or flip over.
If a photon with an energy of 5.0 eV impacts an electron with a binding energy of 4.9 eV what can be said about the electrons motion after impact?
The electron is knocked off the material and has a max kinetic energy of 0.1 eV
Suppose you have two cars, and the larger one is twice as massive as the smaller one. If you and a friend push on them so that their accelerations are equal, how must the forces applied to the cars compare?
The force on the larger car is twice that on the smaller car.
Suppose an object is traveling at terminal velocity, so it is falling through air but not accelerating. How does the force of air resistance compare to its weight?
The two forces are equal and opposite.
You are riding an amusement park ride where you are strapped to the inside of a giant metal wheel that is rotating quite rapidly. Your acceleration is
Toward the center
You are camping in the breathtaking mountains if Colorado. You spy an unopened diet soda can floating motionless below the surface of a lake. What is the direction and amount of force the water exerts on it?
Up, equal to the can's weight
Assume you have a rainbow printed on a piece of paper and you leave it outside in the sunlight for months. Which of the following colors would remain the longest?
Violet
Why are failures in dams more likely to occur closer to the bottom of the dam?
Water pressure is higher at the bottom
The SI unit for power is
Watts
A positive charge and a negative charge will
attract each other
Suppose you go from the earth to a planet where the acceleration of gravity is 2.5 m/s2. On the new planet your weight will be about
be ¼ its value on Earth
1. On a warm, balmy summer day you decide to relax by watching the latest building renovation in your neighborhood. You notice that a very heavy wrecking ball is attached to a much lighter chain and is dangling from a crane and swinging back and forth. As long as it does not swing too high the time it takes the wrecking ball to complete one full oscillation will be independent of
both the amplitude of the motion and the weight of the ball
The first law of thermodynamics is a re - statement of the law of
conservation of energy
Who discovered that matter has a wave nature?
de Broglie
Suppose you are a football player and you kick a ball for a field goal. Including air resistance, the ball's horizontal velocity
decreases throughout the path
You are playing with your younger cousins and find yourself on all fours, with your hands and feet on four bathroom scales on the level ground. You took a "Physics in Everyday Life" course so you can make a reasonable guess that the reading on each scale is obtained by
dividing your weight by 4.
According to Maxwell's equations magnetic field lines do not have to be continuous.
f
According to the second law of thermodynamics, it is theoretically possible for an engine to have an efficiency of 100%.
f
All of Maxwell's predictions were experimentally confirmed before he died.
f
An adiabatic process happens at a constant temperature.
f
Density is defined as the volume per unit mass.
f
Diastolic blood pressure is the maximum blood pressure and the systolic blood pressure is the minimum blood pressure.
f
Electromagnetic radiation can behave like a particle and wave at the same time.
f
Entropy is a measurement of order in a system.
f
Gauge pressure and absolute pressure refer to the exact same value.
f
In general higher-frequency electromagnetic waves are less energetic than lower-frequency waves.
f
In pipe flow, flow rate and velocity are not related.
f
Laminar fluid flow is noisier than turbulent fluid flow.
f
Particles that have mass do not have a wave behavior.
f
The Carnot cycle only uses irreversible processes during the entire cycle.
f
The Gauss (G) is the SI unit for magnetic field strength.
f
The onset of turbulence inside a pipe and around an object in a fluid happens around the same Reynolds number.
f
The total charge is not constant in any process.
f
Thermodynamics is the study of motion and its relationship to position, velocity, and acceleration.
f
Water is the only material that has a triple point in its phase diagram.
f
When a typical solid is heated it shrinks in size.
f
A lightning rod attracts lightning strikes.
false
According to Kepler's second law planets move at a constant speed around the sun no matter where they are relative to the sun.
false
All the energy in an inelastic collision can be completely recovered.
false
An elastic collision conserves internal kinetic energy.
false
An electric field is a scalar quantity.
false
Currently, there are five basic forces that are known.
false
Damping introduced in harmonic motion never affects the period/frequency of the oscillations.
false
Friction is an example of a conservative force.
false
Graphical methods of vector addition and subtraction are more accurate than analytical methods of vector addition and subtraction.
false
Ignoring air resistance and assuming a fixed initial speed, the maximum horizontal range a projectile can travel is when the angle of the projectile is at 35 degrees relative to the ground.
false
Inside a Faraday Cage the electric field is always greater than zero.
false
Insulators allow charges to freely move through material while a conductor does the opposite.
false
Linear momentum and force are not related to each other.
false
Simple harmonic motion and Hooke's Law are not related.
false
Speed and velocity mean the exact same thing.
false
The SI Unit for pressure is psi (pound-per square inch).
false
The first step in solving one-dimensional kinematics problems is to find the relevant equations for the problem.
false
The rotation of the moon around the Earth creates the Coriolis force.
false
The sun has no effect on the Earth's tidal behavior.
false
As the Reynolds number increases,
flow is going from being viscous dominated to inertia dominated and therefore turbulent
Which of the following is not a valid unit of angle measurement?
none
A charged object is able to repel
only charged objects
The north pole of a permanent magnet is clinging to the front surface of your steel refrigerator, so the refrigerator clearly has a south pole at its surface. If you flip the permanent magnet over, so that its south pole faces the refrigerator, the refrigerator will
place a north pole at its surface and attract the permanent magnet
Suppose you are a football player and you kick a ball for a field goal. Ignoring air resistance, the ball's horizontal velocity
remains constant throughout the path
You stick two pieces of adhesive tape on a glass window and then pull them off suddenly. If you now hold the tape pieces near each other, they will be
repelled because they have like charges
A positive charge is moving in the direction of your screen in a magnetic field that points upward. The direction of the force on this positive charge is:
right
The top surface of a calm, smoothly flowing stream is always at atmospheric pressure. As water in this stream runs into a tree stump and slows almost to a stop, the water's top surface
shifts upward slightly above the normal stream level
A popular classroom demonstration is to place a gas can on a burner and boil water in it. Left unchecked this has the potential to be a very boring demo. However the can is removed from the flame and the lid is screwed on tightly. After it cools down the can will
shrivel up, since the atmosphere exerts more force on the can as it cools
You are a superb proposal writer and convince NASA to fund your taking a pendulum clock to Mars (gravity is lower on Mars than Earth) and studying how it runs. Compared to the time it should keep on Earth, the clock will run
slower
A classroom demo that is popular with students and unpopular with custodians is to fill a Styrofoam cup with water, poke a hole in the bottom and then drop the cup into a garbage can waiting below. On the way down, the leak will
stop because the cup and water are both in free fall and locally weightless.
Suppose that you place a timer and a tiny pile of gunpowder in an absolutely rigid box. You then seal the box completely and insulate it perfectly so that no heat can flow in or out of the box. Soon the timer ignites the gunpowder and it burns to form smoke. Since the box is sealed, the smoke remains inside it. If you look into the box a few minutes later, you will find that the smoke has not converted back into the gunpowder because
such an event, unburning the smoke to form gunpowder, is extraordinarily unlikely
A current running through a solenoid produces a magnetic field that nearly matches a bar magnet.
t
A dense fluid (assume mercury) will sink when poured in a less dense fluid (assume water).
t
A nozzle increases the velocity of pipe fluid flow while dropping the pressure of the fluid.
t
A photon has momentum even though it doesn't have any mass.
t
Absolute zero is the temperature where all molecular motion ceases.
t
According to Poiseulle's law a small change in pipe diameter can cause a large change in flow rate.
t
According to the Heisenberg Uncertainty Principle the act of measuring position of a particle inherently changes the momentum of the particle.
t
All mechanical/structural systems have a natural frequency.
t
Assume you have a 100 gram block of ice and a 100 gram glass of liquid water sitting in front of you. In terms of order and disorder the block of ice has more order than the glass of liquid water.
t
Current flows in the same direction as the electric field.
t
Current is the the source of all magnetism.
t
Dams are thicker on the bottom due to the increase in pressure as the water depth increases.
t
Ferromagnetic materials can become permanent magnets.
t
If the amount of current goes up the power consumed also goes up.
t
If the amount of voltage drop in a circuit goes up the power consumed goes down.
t
In an enclosed container when water reaches the boiling temperature at standard atmospheric pressure the water vapor and liquid water near the surface are in equilibrium.
t
James Clerk Maxwell unified electrical and magnetic theory into the electromagnetic theory we know today.
t
Magnetic field lines point in the same direction that the north end of a compass would point.
t
Maxwell's equations predicted the electromagnetic wave that travels at the speed of light.
t
One of the basic requirements of a thermometer is that it must give repeatable results within experimental error.
t
Radio waves, microwaves, and visible light are all considered electromagnetic waves.
t
The lake "turnover" that occurs during the winter season in lakes/ponds is due to temperature-density variation in water.
t
The magnetic force on a moving charge is perpendicular to both the velocity of the moving charge and the magnetic field the charge is passing through at that moment.
t
The sign convention is that current flows in the direction of the positive charges.
t
Turbulent flow is characterized by noisy chaotic mixing fluid flow.
t
When viewed from the proper angle uniform circular motion is a type of simple harmonic motion.
t
When you drop a rubber ball on the floor and it bounces, the direction of its velocity reverses because
the floor exerts an upward support force on the ball and this force stops the ball's descent and eventually propels it upward.
To set the world land speed record and travel faster than the speed of sound, the Thrust SSC vehicle used two jet engines that produced about a 250,000 horsepower. The principal reason why this car needed so much power to travel so fast is that
the pressure drag on a car increases dramatically as the car's speed increases
A squirt gun is a simple type of water pump in which a plunger attached to the trigger forces water out of a nozzle and across the room. When you squeeze the trigger of the gun, water squirts out of the nozzle because
the pressure inside the gun is higher than atmospheric pressure
You are filling a jar of honey from the spigot at the bottom of a large barrel at the grocery store. The honey flows extremely slowly, so the store manager has the barrel refilled. Now the honey flows much more rapidly from the spigot because
the pressure of the honey at the bottom of the barrel increases as the height of honey in the barrel increases
Suppose you have an aquarium and you notice that you have a solid plastic decoration and a rock of about the same volume but twice as dense, and both are totally submerged in the water. The buoyant force on the plastic object is about ___________as that on the rock.
the same
Some engineers have suggested that we can simulate gravity in outer space by having a circular rotating space station where persons feel an outward - directed fictitious force due to the rotation of the station. The reason they feel such a force is because
they are accelerating toward the center of the space station and inertia tends to keep them moving sideways.
A conductor in an electric field will always move its charges till the electric field is perpendicular to its surface.
true
A net external force on an object by definition produces a change in velocity.
true
Acceleration can be defined as the change in velocity with respect to time.
true
According to Newton's third law of motion forces always occur in pairs.
true
As the frequency of an oscillation goes up, the period goes down.
true
Assume a negatively charged rod gets close to a neutral charged surface. The neutral surface will be attracted to the rod by aligning positive charges on the surface.
true
Assume the speed of an object stays the same. If you double the mass of the object the kinetic energy of the object also doubles.
true
Assuming one-dimensional motion, a constant positive acceleration produces a linear increase in velocity.
true
Coulomb's Law and Gravity both have a similar relationship with respect to their dependence on distance.
true
Fictitious forces arise from accelerating reference frames.
true
Gravitational potential energy only depends on the end points and not on the path taken.
true
In 2D kinematics, the two perpendicular vector components of motion are independent of one another.
true
In a vacuum a feather and a bowling ball dropped at the same time from shoulder height will hit the ground at the same time.
true
In the absence of air resistance when you drop a falling ball its speed will steadily increase until it hits the ground.
true
In theory, a projectile can be shot so fast that it can achieve an orbit around the Earth.
true
Multiple stage rockets are an attempt to increase the final velocity of the rocket vehicle as much as possible.
true
Newton's second law can be concisely represented by the following equation: Fnet = ma
true
Power depends on how fast work is done.
true
The force between charged particles decreases with distance.
true
The length of a pendulum affects its period.
true
The shape of a planet's orbit is an ellipse.
true
The tip to tail method only works with two vectors that are added together.
true
When considering real air resistance, a projectile's horizontal motion is reduced throughout flight.
true
When solving problems involving collisions of two point masses in two dimensions, a convenient coordinate system is usually chosen.
true
The reason fast-moving water makes noise is
turbulence
You open the refrigerator in your room and put in a case of room-temperature root beer. After an hour, the root beer is ice cold. If your room air did not exchange any heat with the outdoor air during that time, the room air will be
warmer because the refrigerator will have pumped heat out of the root beer and into the room air.
In a popular classroom demonstration, a cotton ball is placed in the bottom of a strong test tube. A plunger fits inside the tube and it makes an air - tight seal. It is then pushed down very rapidly, and the cotton flashes and burns. This happens because
when the air was compressed its temperature increased
You and a friend are spending the weekend making up missed lab experiments. You are studying the electrostatic interaction of two charges. You notice that two charges are exerting a certain force on one another. If the distance between two electric charges doubles, then the force they exert on each other changes by how much?
¼ as large
