physics final
A 10-N falling object encounters 10 N of air resistance. The net force on the object is
0 N
An apple weighs 1 N. When held at rest above your head, the net force on the apple is
0 N
When a 60-watt light bulb is connected to a 120-volt source the current in the light bulb is
0.5 A
A 1-kg ball is thrown at 10 m/s straight upward. Neglecting air resistance, the net force that acts on the stone when it is halfway to the top of its path is about
10 N
It takes 40 J to push a large box 4 m across a floor. Assuming the push is in the same direction as the move, what is the magnitude of the force on the box?
10 N
The force of friction on a sliding object is 10 N. The applied force needed to maintain a constant velocity is
10 N
Three resistors, 1-ohm, 2-ohm, and 3- ohm are connected in parallel. If they were connected in series instead their equivalent resistance would be
11 times as great
A car moving at 50 km/hr skids 20 m with locked brakes. How far will the car skid with locked brakes if it were traveling at 150 km/hr?
180 m
A 4-ohm resistor is connected in parallel with a 6-ohm resistor. This combination produces an equivalent resistance of
2.4 ohms
The electric power of a lamp that carries 2 A at 120 V is
240 W
The electric power of a lamp that carries 2 A at 120 V is
240 watts
A TV set is pushed a distance of 2 m with a force of 20 N. How much work is done on the set?
40 J
A man weighing 800 N stands at rest on two bathroom scales so that his weight is distributed evenly over both scales. The reading on each scale is
400 N
A 10-kilogram block with an initial velocity of 10 m/s slides 10 meters across a horizontal surface and comes to rest. It takes the block 2 seconds to stop. The stopping force acting on the block is about
50 N
Two 5000-kg passenger cars roll without friction (one at 1 m/s, the other at 2 m/s) toward each other on a level track. They collide, couple, and roll away together with a combined momentum of
5000 kg m/s
A 2-kg mass is held 4 m above the ground. What is the approximate potential energy of the mass with respect to the ground?
80 J
When U-238 emits an alpha particle, the nucleus left behind has
90 protons
Compared to the recoiling rifle, the bullet fired has
A greater kinetic energy
In a common dc circuit, electrons move at speeds of
a fraction of a centimeter per second.
Electrons are made to flow in a wire when there is
a potential difference across its ends.
A bag of groceries has a mass of 10 kilograms and a weight of
about 100 N
It takes 6 seconds for a stone to fall to the bottom of a mine shaft. How deep is the shaft?
about 180 m
Hang from a pair of gym rings and the upward support forces of the rings will always
add up to equal your weight
Light from a laser is
all of these
Which has zero acceleration? An object
all of these
In the process of fluorescence, part of the input energy immediately
becomes internal energy and the rest lower frequency light
A mixture of red and green pigments appears
blackish brown
What color light is transmitted by a piece of blue glass?
blue
Eratosthenes learned about the position of the sun on June 22 by
consulting library information.
Science and technology are
different
Different colors of light correspond to different light
frequency
When a rocket ship accelerating in outer space runs out of fuel, it
no longer accelerates
What is the resistance of a 120-W incandescent lamp connected to a 120-V power supply?
none of these
An object falls freely from rest on a planet where the acceleration due to gravity is twice as much as it is on Earth. In the first 5 seconds it falls a distance of
250 m
The power dissipated in a 4-ohm resistor carrying 3 A is
36 W
Two people, one twice as massive as the other, attempt a tug-of-war with 12 meters of massless rope on frictionless ice. After a brief time, they meet. The heavier person slides a distance of
4 m
A bow is drawn so that it has 40 J of potential energy. When fired, the arrow will ideally have a kinetic energy that is
40 J
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?
5
A jack system will increase the potential energy of a heavy load by 1000 J with a work input of 2000 J. The efficiency of the jack system is
50 %
Using 1000 J of work, a toy elevator is raised from the ground floor to the second floor in 20 seconds. The power needed to do this job was
50 W
The force required to maintain an object at a constant velocity in free space is equal to
zero
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
2.20$
A 500-N parachutist opens his chute and experiences an air resistance force of 800 N. The net force on the parachutist is
300 N upward
When U-239 emits a beta particle, the nucleus left behind has
93 protons
In a simple circuit containing a bulb, energy is given to the moving charges by
a generator
Science is a body of knowledge that
all of the above
A truly educated person is knowledgeable about
all of these
Compared to a 1-kg block of solid iron, a 2-kg block of solid iron has twice as much
all of these
A capacitor is used to store
both
When a rifle is fired, it recoils as the bullet is set in motion. The rifle and bullet ideally acquire equal
but opposite amounts of momentum
A large and a small person wish to parachute at equal terminal velocities. The larger person will have to
get a larger parachute
A mixture of cyan and yellow pigments appears
green
A skydiver's terminal velocity will be greatest if she falls
head first
If one object has twice as much mass as another object, it also has twice as much
inertia
Uranium-235, uranium-238 and uranium-239 are different
isotopes
in which case would you have the largest mass of gold? If your chunk of gold weighed 1 N on the
moon
Compared to the energy of a photon of red light, the energy of a photon of blue light is
more
Compared to a single lamp connected to a battery, two lamps connected in parallel to the same battery will carry
more current
As a ball falls, the action force is the pull of Earth on the ball. The reaction force is the
pull of the ball's mass on the Earth.
Magenta light is really a mixture of
red and blue light
The colored dots that make up the color on a TV screen are
red, blue, green.
The color of an opaque object is the same as the light that is
reflected
The statement, "There are regions beneath the Earth's crust that will always be beyond the reach of scientific investigation," is a
speculation.
A 60-W light bulb and a 100-W light bulb are each rated at 120 V. Which light bulb has a larger resistance?
the 60 W bulb
Two lamps, one with a thick filament and one with a thin filament, are connected in parallel to a battery. The voltage is
the same in both lamps
Two lamps, one with a thick filament and one with a thin filament, are connected in series. The current is
the same in each lamp
If an object is raised twice as high, its potential energy will be
twice as much
One end of a long, uniform log is raised to shoulder level. Another identical log is raised at its center to the same level. Raising the second log requires about
twice as much
If you push an object twice as far while applying the same force, you do
twice as much work
The highest frequency light of those below is
violet
Which color of light carries the most energy per photon?
violet
A falling skydiver of mass 100 kg experiences 500 N of air resistance. The acceleration of the skydiver is
0.5 g
An object at rest near the surface of a distant planet starts to fall freely. If the acceleration there is twice that of the Earth, its speed one second later would be
20 m/s
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
220 ohms
A ride on a roller-coaster car containing 6 passengers takes 3 minutes. Neglecting friction, a similar ride with 12 passengers aboard would take
3 min
A sphere has a negative charge of 6.4 × 10-7 coulomb. The approximate number of electrons that must be removed to make the sphere neutral is
4.0 x 10 ^12
A sphere has a negative charge of 6.4 × 10-7 coulomb. The approximate number of electrons that must be removed to make the sphere neutral is
4.0 × 10^12
Suppose a miracle car has a 100% efficient engine and burns fuel that has a 40-megajoules-per-liter energy content. If the air drag and overall frictional forces on this car traveling at highway speeds total 1000 N, what is the overall limit in distance per liter it could be driven on the highway?
40 km
When a 10-V battery is connected to a resistor, the current in the resistor is 2 A. What is the resistor's value?
5 ohms
A coulomb of charge that passes through a 6-volt battery is given
6 joules
A 1-kg mass at the Earth's surface weighs
9.8 N
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 thick filament
A pot falls from a ledge and hits the ground 45 m below. The speed with which it hits the ground is
about 30 m/s
A ball is thrown upwards. Neglecting air resistance, what initial upward speed does the ball need to remain in the air for a total time of 10 seconds?
about 50 m/s
The human body can, under certain conditions, withstand an acceleration of 10 g. What net force would produce this acceleration of a 50-kg person?
about 5000 N
Which of the following involves passion, talent, and intelligence?
all of these
In the fissioning of uranium, a chain reaction is caused by
ejected neutrons
A 60-W light bulb and a 100-W light bulb are connected in series to a 120 V outlet. Which light bulb has more current in it?
electron kinetic energy is changed into heat.
If your automobile runs out of fuel while you are driving, the engine stops but you do not come to an abrupt stop. The concept that most explains why is
inertia
In science, facts
may change
When two lamps are connected in series to a battery, the electrical resistance that the battery senses is
more than the resistance of either lamp
Modern automobile headlights are connected in
parallel
The headlights, radio, and defroster fan in an automobile are connected in
parallel with a switch for each
The white light emitted by a fluorescent lamp is provided by the
phosphors on the inner surface of the lamp.
The safest way for you to view the sun is with
pinhole images.
A capacitor is useful in
smoothing pulsed current
Stretch a copper wire so that it is thinner and the resistance between its ends
increases
The ball rolling down an incline has its maximum potential energy at
the top
A push on a 1-kg brick accelerates it. Neglecting friction, to equally accelerate a 10-kg brick, one would have to push with
10 times as much force.
A block is dragged without acceleration in a straight-line path across a level surface by a force of 6 N. What is the force of friction between the block and the surface?
6 N
If 0.8 A of current flow through a light bulb connected to a 120 V outlet, the power consumed is
96 W
The source of electrons lighting an incandescent ac light bulb is
atoms in the light bulb filament
An ampere is a unit of electrical
current
As more lamps are put into a series circuit, the overall current in the power source
decreases
An object is propelled along a straight-line path in space by a force. If the mass of the object somehow becomes twice as much, its acceleration
halves
Two objects of the same size, but unequal weights are dropped from a tall tower. Taking air resistance into consideration, the object to hit the ground first will be the
heavier object
In science, an educated guess is a
hypothesis
A woman experiences an electrical shock. The electrons making the shock come from the
womans body
A scientific hypothesis may turn out to be right or it may turn out to be wrong. If it is a valid hypothesis, there must be a test for proving it
wrong
A car maintains a constant velocity of 100 km/hr for 10 seconds. During this interval its acceleration is
zero
A 10-N block and a 1-N block lie on a horizontal frictionless table. To provide them with equal horizontal acceleration, we would have to push with
10 times as much force on the heavier block.
Neglecting air resistance, a man on a high ladder releases a ball which strikes the ground with 100 J of kinetic energy. If he were to throw it straight upward instead, it will eventually reach the ground with a kinetic energy of
100 J
A car accelerates at 2 meters/s/s. Assuming the car starts from rest, how far will it travel in 10 s?
100 m
In a 110-volt circuit containing a lamp in series with the voltage source
110 joules of energy are given up by each coulomb of charge making up the current in the circuit.
An object released from rest on another planet requires one second to fall a distance of 6 meters. What is the acceleration in meters per second per second due to gravity on this planet?
12
A power line with a resistance of 2 ohms has a current of 80 A in it. The power dissipated in the line is
12,800 W
When two 1-ohm resistors are connected in series, their combined resistance is
2 ohms, and when in parallel, 1/2 ohm.
A 1000-kg automobile enters a freeway on-ramp at 20 m/s and accelerates uniformly up to 40 m/s in a time of 10 seconds. How far does the automobile travel during that time?
300 m
A 300-kg bear grasping a vertical tree slides down at constant velocity. The friction force between the tree and the bear is
3000N
A person is attracted toward the center of Earth by a 500-N gravitational force. The Earth is attracted toward the person with a force of
500 N
A bullet is fired straight down from the top of a high cliff. Neglecting air resistance, the acceleration of the bullet in meters per second per second
9.8
Which of the following is a scientific statement?
The moon is made of green cheese.
A whitish sky is evidence that the atmosphere contains
a mixture of particle sizes
A ball is thrown 125 meters upward and then falls the same distance back to Earth. Neglecting air resistance, its total time in the air is
about 10 sec
A heavy and a light object released from the same height in a vacuum have equal
accelerations
The greater proportion of energy immediately converted to heat rather than light occurs in
an incandescent lamp
electrons move in an electrical circuit
by interacting with an established electric field
Electrons move in an electrical circuit
by interacting with an established electric field.
If an object moves with constant acceleration, its velocity must
change by the same amount each second.
In an ac circuit, the electric field
changes magnitude and direction with time
An electrical diode is useful for
changing ac to dc
Your car is coasting on level ground at 60 km/h and you apply the brakes until the car slows to 40 km/h. If you suddenly release the brakes now, the car tends to
continue moving at 40 km/h
If no external forces are acting on a moving object, it will
continue moving at the same velocity.
When we say an appliance "uses up electricity," we really are saying that
electron kinetic energy is changed into heat
A circuit breaker often serves the same purpose as a
fuse
The scientific method is most effective in
gaining, organizing, and applying new knowledge
Light shines on a pane of green glass and a pane of clear glass. The temperature will be higher in the
green glass
As more lamps are put into a parallel circuit, the overall current in the power source
increases
In each second of fall, the distance a freely falling object will fall is
increasing
The nucleus with the most tightly bound nucleons is
iron
A lightweight feather slides off a table and falls through the air until it reaches the floor. During the time of its fall, its acceleration
is sometimes zero
A skydiver steps from a helicopter and falls for a few seconds until he reaches his terminal velocity. Thereafter, until he opens his parachute, his acceleration
is zero
Color depends on what characteristic of light?
its frequency
Compared to a single lamp connected to a battery, two identical lamps connected in series to the same battery will carry
less current
When a light switch is turned on in a dc circuit, the average speed of electrons in the lamp is
less than 1 cm/s
A ball is projected into the air with 100 J of kinetic energy which is transformed to gravitational potential energy at the top of its trajectory. When it returns to its original level after encountering air resistance, its kinetic energy is
less than 100 J
An object may have potential energy because of its
location
A bullet has more kinetic energy than the recoiling rifle from which it is fired is because the force on the bullet acts over a
longer distance
Light is emitted when an electron
makes a transition to a lower energy level.
A wire that carries an electric current
may be electrically charged.
Connect a pair of lamps in series and you draw current from the connected battery. Connect the same lamps in parallel and you draw
more current
Someone standing at the edge of a cliff throws one ball straight up and another ball straight down at the same initial speed. Neglecting air resistance, the ball to hit the ground below the cliff with the greater speed will be
neither
When an object is in motion, which of the following could not have a value of zero?
none of the above could be zero
Of the sciences known as physics, chemistry, and biology, the most basic is
physics
The sky is blue because air molecules in the sky act as tiny
resonators which scatter blue light.
The force exerted on the tires of a car to directly accelerate it along a road is exerted by the
road
Galileo's use of inclined planes allowed him to effectively
slow down the acceleration of free fall.
Two identical freight cars roll without friction (one at 1 m/s, the other at 2 m/s) toward each other on a level track. They collide, couple together, and roll away in the direction that
the faster car was initially going
your weight is
the gravitational attraction between you and the Earth.
A sheet of paper can be withdrawn from under a container of milk without toppling it if the paper is jerked quickly. This best demonstrates that
the milk carton has inertia
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?
the one on the moon
Compared to the amount of electric current in the filament of a lamp, the amount of current in the connecting wire is
the same
After rolling halfway down an incline, a marble's kinetic energy is
the same as its potential energy.
A car traveling at 100 km/hr strikes an unfortunate bug and splatters it. The force of impact is
the same for both
The synthesis of a large collection of information that contains well-tested and verified hypotheses about certain aspects of the world is known as a scientific
theory
Compared to the filament thickness of a 60-W light bulb, the filament of a 100-W light bulb will be
thicker
A circuit is powered with a battery. Charge flows
through both the battery and the rest
A circuit is powered with a battery. Charge flows
through both the battery and the rest of the circuit.
Which is more dangerous, touching a faulty 110-volt light fixture, or a Van de Graaff generator charged to 100,000 volts?
touching the light fixture
Strictly speaking, more fuel is consumed by your car if an air conditioner, headlights, or even a radio is turned on. This statement is
true
A 1000-kg car and a 2000-kg car are hoisted the same distance. Raising the more massive car requires
twice as much work
If you plug an electric toaster rated at 110 V into a 220-V outlet, the current in the toaster will be about
twice what it should be
Fluorescent minerals on display in museums are illuminated with
ultraviolet light
When a rock thrown straight upwards gets to the exact top of its path, its
velocity is zero and its acceleration is about 10 meters per second per second
A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are neglected, the force required to keep the puck sliding at constant velocity is
zero
The number of electrons delivered daily to an average American home by an average power utility in the mid 1980s was
zero
When a falling object has reached its terminal velocity, its acceleration is
zero
A sack of potatoes weighing 200 N falls from an airplane. As the velocity of fall increases, air resistance also increases. When air resistance equals 200 N, the sack's acceleration in meters per second per second is
0
An apple falls from a tree and hits the ground 5 meters below. It hits the ground with a speed of about
10 m/s
If a freely falling object were somehow equipped with a speedometer, its speed reading would increase each second by about
10 m/s
The current through a 10-ohm resistor connected to a 120-V power supply is
12A
If a projectile is fired straight up at a speed of 10 m/s, the total time to return to its starting position is about
2 sec
Science, art, and religion do not contradict one another because
all three have different domains.
Earth pulls on the moon. Similarly the moon pulls on Earth, evidence that
These two pulls comprise an action-reaction pair
A feather and a coin dropped in a vacuum fall with equal
accelerations
An object in mechanical equilibrium is an object
all of these
According to Newton's law of inertia, a railroad train in motion should continue going forever even if its engine is turned off. We never observe this because railroad trains
always have forces that oppose their motion.
A 60-W light bulb and a 100-W light bulb are connected in series to a 120 V outlet. Which light bulb has more current in it?
both have the same current **
A skydiver jumps from a high-flying plane. As her velocity of fall increases, her acceleration
decreases
A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. During this time the acceleration of the ball is always
directed downward
The variety of colors seen in a burning log comes from the variety of
electron transitions in various atoms.
A truck is moving at constant velocity. Inside the storage compartment, a rock is dropped from the midpoint of the ceiling and strikes the floor below. The rock hits the floor
exactly below the midpoint of the ceiling.
Whereas Aristotle relied on logic in explaining nature, Galileo relied on
experiment
Alternating current is normally produced by a
generator
When a scientist is dishonest and reports false information, he or she
gets no second chance in the scientific community
A heavy rock and a light rock of the same size are falling through the air from a tall building. The one that encounters the greatest air resistance is the
heavy rock
As more lamps are put into a series circuit, the overall current in the power source
increases
Heat a copper wire and its electric resistance
increases
A 100-Watt lamp glows brighter than a 25-Watt lamp. The electrical resistance of the 100-Watt lamp must be
less
Compared to the resistance of two resistors connected in series, the same two resistors connected in parallel have
less resistance
When two lamps are connected in parallel to a battery, the electrical resistance that the battery senses is
less than the resistance of either lamp.
In the process of fluorescence, the input is high-frequency light and the output is
lower frequency light
A 10-ohm resistor has a 5-A current in it. What is the voltage across the resistor?
more than 20 V
What condition must exist between two points in a conductor in order to maintain a flow of charge?
none of the above
A wire carrying a current is normally charged
not at all
the ratio of the potential difference across a metallic conductor to the current in the conductor is known as
resistance
Two lamps, one with a thick filament and one with a thin filament, are connected in parallel to a battery. The voltage is
same in both lamps
In an electric circuit, the safety fuse is connected to the circuit in
series
On some early automobiles both headlights went out when one bulb burned out. The headlights must have been connected in
series
Galileo's use of inclined planes allowed him to effectively
slow down the acceleration of free fall
The primary source of electrons in an ordinary electrical circuit is
the electrical circuit itself
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
the same electron
