Term
Can work be done on a system if there is no motion?
A) Yes, if an outside force is provided.
B) Yes, since motion is only relative.
C) No, since a system which is not moving has no energy. D) No, because of the way work is defined. 

Definition
D) No, because of the way work is defined. 


Term
If you push twice as hard against a stationary brick wall, the amount of work you do
A) doubles.
B) is cut in half.
C) remains constant but nonzero.
D) remains constant at zero. 

Definition
D) remains constant at zero. 


Term
A 50N object was lifted 2.0 m vertically and is being held there. How much work is being done in holding the box in this position?
A) more than 100 J
B) 100 J
C) less than 100 J, but more than 0 J
D) 0 J


Definition


Term
If you walk 5.0 m horizontally forward at a constant velocity carrying a 10N object, the amount of work you do is
A) more than 50 J.
B) equal to 50 J.
C) less than 50 J, but more than 0 J.
D) zero. 

Definition


Term
Does the centripetal force acting on an object do work on the object?
A) Yes, since a force acts and the object moves, and work is force times distance.
B) Yes, since it takes energy to turn an object.
C) No, because the object has constant speed.
D) No, because the force and the displacement of the object are perpendicular.


Definition
D) No, because the force and the displacement of the object are perpendicular. 


Term
You throw a ball straight up. Compare the sign of the work done by gravity while the ball goes up with the sign of the work done by gravity while it goes down.
A) Work is + on the way up and + on the way down.
B) Work is + on the way up and  on the way down.
C) Work is  on the way up and + on the way down.
D) Work is  on the way up and  on the way down.


Definition
C) Work is  on the way up and + on the way down. 


Term
The area under the curve, on a Force versus position (F vs. x) graph, represents
A) work.
B) kinetic energy.
C) power.
D) potential energy.


Definition


Term
The quantity 1/2 mv2 is
A) the kinetic energy of the object.
B) the potential energy of the object.
C) the work done on the object by the force.
D) the power supplied to the object by the force. 

Definition
A) the kinetic energy of the object. 


Term
If the net work done on an object is positive, then the object's kinetic energy
A) decreases.
B) remains the same.
C) increases.
D) is zero. 

Definition


Term
If the net work done on an object is negative, then the object's kinetic energy
A) decreases.
B) remains the same.
C) increases.
D) is zero.


Definition


Term
If the net work done on an object is zero, then the object's kinetic energy
A) decreases.
B) remains the same.
C) increases.
D) is zero. 

Definition


Term
An object hits a wall and bounces back with half of its original speed. What is the ratio of the final kinetic energy to the initial kinetic energy?
A) 1/2
B) 1/4
C) 2
D) 4 

Definition


Term
You slam on the brakes of your car in a panic, and skid a certain distance on a straight, level road. If you had been traveling twice as fast, what distance would the car have skidded, under the same conditions?
A) It would have skidded 4 times farther.
B) It would have skidded twice as far.
C) It would have skidded 1.4 times farther.
D) It is impossible to tell from the information given. 

Definition
A) It would have skidded 4 times farther. 


Term
A planet of constant mass orbits the Sun in an elliptical orbit. Neglecting any friction effects, what happens to the planet's kinetic energy?
A) It remains constant.
B) It increases continually.
C) It decreases continually.
D) It increases when the planet approaches the Sun, and decreases when it moves farther away. 

Definition
D) It increases when the planet approaches the Sun, and decreases when it moves farther away. 


Term
The quantity mgy is
A) the kinetic energy of the object.
B) the gravitational potential energy of the object.
C) the work done on the object by the force.
D) the power supplied to the object by the force. 

Definition
B) the gravitational potential energy of the object. 


Term
The quantity 1/2 kx^2 is
A) the kinetic energy of the object.
B) the elastic potential energy of the object.
C) the work done on the object by the force.
D) the power supplied to the object by the force.


Definition
B) the elastic potential energy of the object. 


Term
An acorn falls from a tree. Compare its kinetic energy K, to its potential energy U.
A) K increases and U decreases.
B) K decreases and U decreases.
C) K increases and U increases.
D) K decreases and U increases. 

Definition
A) K increases and U decreases. 


Term
A ball falls from the top of a building, through the air (air friction is not present), to the ground below. How does the kinetic energy (K) just before striking the ground compare to the potential energy (U) at the top of the building?
A) K is equal to U.
B) K is greater than U.
C) K is less than U.
D) It is impossible to tell. 

Definition


Term
A ball falls from the top of a building, through the air (air friction is present), to the ground below. How does the kinetic energy (K) just before striking the ground compare to the potential energy (U) at the top of the building?
A) K is equal to U.
B) K is greater than U.
C) K is less than U.
D) It is impossible to tell. 

Definition


Term
A 500kg elevator is pulled upward with a constant force of 5500 N for a distance of 50.0 m. What is the work done by the 5500 N force? 

Definition
2.75 × 105 J (W=Fd cosθ=F^{.}d) 


Term
A 500kg elevator is pulled upward with a constant force of 5500 N for a distance of 50.0 m. What is the work done by the weight of the elevator? 

Definition
2.45 × 105 J (W=F^{.}d=mgh) 


Term
4.00kg box of fruit slides 8.0 m down a ramp, inclined at 30.0° from the horizontal. If the box slides at a constant velocity of 5.00 m/s, what is the work done by the weight of the box? 

Definition
157 J (W =F^{.}d, F= F_{x}= mgsinθ, d=8) ) or (W=Fd cosθ, F=mg, θ=9030, d=8) 


Term
A horizontal force of 200 N is applied to move a 55kg cart (initially at rest) across a 10 m level surface. What is the final kinetic energy of the cart? 

Definition
2.0 × 103 J (ΣW=ΔKE= F^{.}d) 


Term
A horizontal force of 200 N is applied to move a 55kg cart (initially at rest) across a 10 m level surface. What is the final speed of the cart? 

Definition
8.5 m/s (ΣW=ΔKE= F^{.}d=½mv^{2}) 


Term
A springdriven dart gun propels a 10g dart. It is cocked by exerting a force of 20 N over a distance of 5.0 cm. With what speed will the dart leave the gun, assuming the spring has negligible mass? 

Definition
14 m/s (ΣW=ΔKE= F^{.}d=½mv^{2}) (20N constant force NOT dependant on displacement of spring) (½kx^{2 }assumes force varies with distance) 


Term
An arrow of mass 20 g is shot horizontally into a bale of hay, striking the hay with a velocity of 60 m/s. It penetrates a depth of 20 cm before stopping. What is the average stopping force acting on the arrow? 

Definition
180 N (F^{.}d=½mv^{2}) (ΣW=ΔKE) 


Term
A 400N box is pushed up an inclined plane. The plane is 4.0 m long and rises 2.0 m. If the plane is frictionless, how much work was done by the push? 

Definition


Term
A spring is characterized by a spring constant of 60 N/m. How much potential energy does it store, when stretched by 1.0 cm? 

Definition
3.0 × 103 J (½kx^{2} =EPE)



Term
A 60kg skier starts from rest from the top of a 50m high slope. What is the speed of the slier on reaching the bottom of the slope? (Neglect friction.) 

Definition
31 m/s (½mv^{2}=mgh) (ΔKE=GPE) 


Term
A 1500kg car moving at 25 m/s hits an initially uncompressed horizontal spring with spring constant of 2.0 × 106 N/m. What is the maximum compression of the spring? (Neglect the mass of the spring.)


Definition
0.68 m (½mv^{2} =½kx^{2 } ΔKE =EPE) 


Term
A 60kg skier starts from rest from the top of a 50m high slope. If the work done by friction is 6.0 × 103 J, what is the speed of the skier on reaching the bottom of the slope? 

Definition
28 m/s (ΣW=ΔKE) (ΣW=mghW_{f}= ½mv^{2}) 


Term
At what rate is a 60.0kg boy using energy when he runs up a flight of stairs 10.0m high, in 8.00 s? 

Definition


Term
A 10N force is needed to move an object with a constant velocity of 5.0 m/s. What power must be delivered to the object by the force? 

Definition


Term
A 1500kg car accelerates from 0 to 25 m/s in 7.0 s. What is the average power delivered by the engine? (1 hp = 746 W) 

Definition
90 hp (P=W/t) (ΣW=ΔKE½mv^{2}) 


Term
According to Kepler's laws, the paths of planets about the sun are
A) circles.
B) straight lines.
C) ellipses.
D) parabolas.
E) none of these.


Definition


Term
Newton discovered
A) gravity.
B) that gravity is universal.
C) neither. 

Definition
B) that gravity is universal. 


Term
According to Newton, the greater the masses of interacting objects, the
A) greater the gravitational force between them.
B) less the gravitational force between them.
C) greater the force between them by the square of the masses.


Definition
A) greater the gravitational force between them. 


Term
According to Newton, doubling the distance between two interacting objects
A) multiplies by 2 the gravitational force between them.
B) multiplies by 4 the gravitational force between them.
C) divides by 4 the gravitational force between them.
D) divides by 2 the gravitational force between them. 

Definition
C) divides by 4 the gravitational force between them. 


Term
What is the force of gravity on a 500newton woman standing on the Earth's surface?
A) 50 N
B) 250 N
C) 500 N
D) 509.8 N. 

Definition


Term
If the mass of the Earth somehow increased with no change in radius, your weight would
A) decrease. B) increase also. C) stay the same. 

Definition


Term
Inside a freelyfalling elevator, there would be no
A) apparent weight for you.
B) gravitational force on you.
C) both of these.
D) none of these. 

Definition
A) apparent weight for you. 


Term
A supplier wants to make a profit by buying metal by weight at one altitude and selling it at the same price per pound at another altitude. The supplier should
A) buy at a low altitude and sell at a high altitude.
B) disregard altitude because it makes no difference.
C) buy at a high altitude and sell at a low altitude. 

Definition
C) buy at a high altitude and sell at a low altitude. 


Term
If the sun somehow became twice as massive, your weight as normally measured here on earth would
A) not change. B) double. C) quadruple. 

Definition


Term
How far must one travel to get away from the Earth's gravitational field?
A) to a region beyond the solar system
B) to a region above the Earth's atmosphere
C) to a region well beyond the moon
D) ...forget it; you can't travel far enough. 

Definition
D) ...forget it; you can't travel far enough. 


Term
When a star collapses to form a black hole, its mass
A) decreases. B) increases. C) remains the same. 

Definition


Term
The Earth is currently accelerating toward the sun (centripetal acceleration). If the sun collapsed into a black hole, this acceleration would
A) stay the same.
B) cease to exist.
C) increase.
D) decrease.


Definition


Term
If the sun collapsed to a black hole, the Earth's gravitational attraction to it would be
A) more. B) the same. C) less. 

Definition


Term
The factor most directly responsible for making a black hole invisible is its
A) size.
B) color.
C) surface escape velocity.
D) mass.
E) none of these. 

Definition
C) surface escape velocity. 


Term
The reason the moon does not crash into the Earth is that the
A) gravitational pull of other planets keeps the moon up.
B) moon has a sufficient tangential speed.
C) moon has less mass than the Earth.
D) Earth's gravitational field is weak at the moon.
E) none of these. 

Definition
B) moon has a sufficient tangential speed. 


Term
Inside a freelyfalling runaway elevator, your
A) acceleration is zero.
B) gravitational interaction with the Earth is zero.
C) apparent weight is zero.
D) all of these.
E) none of these. 

Definition
C) apparent weight is zero. 


Term
If you drop a stone into a hole drilled all the way to the other side of the Earth (neglect the molten core), the stone will
A) slow down until it reaches the center.
B) speed up until it reaches the other side of the Earth.
C) come to an abrupt stop at the center of the Earth.
D) speed up until it gets to the center of the Earth. 

Definition
D) speed up until it gets to the center of the Earth. 


Term
Horses that move with the fastest linear speed on a merrygoround are located
A) near the center.
B) anywhere because they all move at the same speed.
C) near the outside. 

Definition


Term
Horses that move with the fastest linear speed on a merrygoround are located
A) near the center.
B) anywhere because they all move at the same speed.
C) near the outside. 

Definition


Term
If you use largediameter tires on your car, for a given RPM your linear speed will be
A) less. B) more. C) no different. 

Definition


Term
If a record player's rotational speed is doubled, then the linear speed of a pet hamster sitting on the edge of the record will
A) halve. B) double. C) remain the same. 

Definition


Term
An upright broom is easier to balance when the heavier end is
A) highest, farthest from your hand.
B) nearest your hand.
C) same either way. 

Definition
A) highest, farthest from your hand. 


Term
An industrial flywheel has a greater rotational inertia when most of its mass is
A) nearest the rim.
B) uniformly spread out as in a disk.
C) nearest the axis. 

Definition


Term
A coin and a ring roll down an incline starting at the same time. The one to reach the bottom first will be the
A) ring.
B) coin.
C) both reach the bottom at the same time. 

Definition


Term
A torque acting on an object tends to produce
A) rotation.
B) velocity.
C) equilibrium.
D) a center of gravity.
E) linear motion. 

Definition


Term
On a balanced see saw, a boy three times as heavy as his partner sits
A) more than 1/3 the distance from the fulcrum.
B) less than 1/3 the distance from the fulcrum.
C) 1/3 the distance from the fulcrum. 

Definition
C) 1/3 the distance from the fulcrum. 


Term
Put a pipe over the end of a wrench when trying to turn a stubborn nut on a bolt, to effectively make the wrench handle twice as long, you'll multiply the torque by
A) two. B) four. C) eight. 

Definition


Term
Toss a baseball bat into the air and it wobbles about its
A) geometrical center.
B) heavier end.
C) center of mass. 

Definition


Term
The famous Leaning Tower of Pisa doesn't topple over because its center of gravity is
A) above a place of support.
B) relatively low for such a tall building.
C) in the same place as its center of mass.
D) stabilized by its structure.
E) displaced from its center. 

Definition
A) above a place of support. 


Term
When a twirling ice skater brings her arms inward, her rotational speed
A) decreases. B) remains the same. C) increases. 

Definition


Term
A tightrope walker more easily balances on a tightwire if his pole
A) is short but heavy. B) droops. C) is held high. 

Definition


Term
A ring, a disk, and a solid sphere begin rolling down a hill together. The one to reach the bottom first is the
A) disk.
B) ring.
C) sphere.
D) they all reach the bottom at the same time.
E) not enough information is given. 

Definition


Term
Suppose you put very largediameter tires on your car. Then, your speedometer will show a speed that is
A) lower than it is actually.
B) higher than it is actually. 

Definition
A) lower than it is actually. 


Term
If you push an object twice as far while applying the same force you do
A) the same amount of work.
B) twice as much work.
C) four times as much work. 

Definition


Term
A job is done slowly, while an identical job is done quickly. Both jobs require the same amount of work, but different amounts of
A) energy. B) power. C) both of these. D) none of these. 

Definition


Term
Exert 1 N for a distance of 1 m in 1 s and you deliver a power of
A) 1 W.
B) 2 W.
C) 1/3 W.
D) 3 W.
E) none of these.


Definition


Term
When an object is raised above the ground it gains a certain amount of potential energy. If the same object is raised twice as high it gains
A) four times as much potential energy.
B) twice as much potential energy.
C) neither of these. 

Definition
B) twice as much potential energy. 


Term
An object that has kinetic energy must be
A) falling.
B) at rest.
C) at an elevated position.
D) moving.
E) none of these. 

Definition


Term
Bullets are fired from an airplane in the forward direction of motion. The momentum of the airplane will be
A) increased. B) decreased. C) unchanged. 

Definition


Term
A bow is drawn so that it has 40 J of potential energy. When fired, the arrow will ideally
A) 40 J. B) more than 40 J. C) less than 40 J. have a kinetic energy of 

Definition


Term
When a car is braked to a stop, its kinetic energy is transformed to
A) energy of motion.
B) potential energy.
C) heat.
D) stopping energy.
E) energy of rest. 

Definition


Term
A car moves 4 times as fast as another identical car. Compared to the slower car, the faster car has
A) 4 times the KE.
B) 8 times the KE.
C) 12 times the KE.
D) 16 times the KE. 

Definition


Term
A woman lifts a box from the floor. She then moves with constant speed to the other side of the room, where she puts the box down. How much work does she do on the box while walking across the floor at constant speed?
A) zero J
B) more than zero J
C) more information needed to determine


Definition


Term
According to Kepler's laws, the paths of planets about the Sun are


Definition


Term
According to Newton, the greater the masses of interacting objects, the 

Definition
greater the force of gravity, by the product of the masses
F = G M m / d^{^2}



Term
According to Newton, the greater the distance between masses of interacting objects, the 

Definition
less the force of gravity, inversely as the square of the distance
F = G M m / d^^{2}



Term
If the mass of the earth somehow increased with no change in radius, your weight would 

Definition
increase
F = G M m / d^{^2}



Term
If the radius of Earth somehow decreased with no change in mass, your weight would 

Definition
increase
F = G M m / d^{2}



Term
If Earth's mass decreased to onehalf its original mass with no change in radius, then your weight would 

Definition
decrease to onehalf its original value
F = G M m / d^{2}



Term
The force of gravity acting on the Space Shuttle in orbit is nearly 

Definition
equal to the weight of the Space Shuttle at Earth's surface
F = G M m / d^{2}
In a lowEarth orbit, the Space Shuttle's distance from the center of Earth is nearly the same as it was at Earth's surface.



Term
A woman who normally weighs 400 N stands on top of a very tall ladder so she is one earth radius above the earth's surface. How much would she weigh there? 

Definition
100 N
F = G M m / d^{2}
If d is made twice as large, then d^{2} will be four times as large. Since we are dividing by d^{2}, this means the Force  her weight  will be only onefourth as much.



Term
The force of gravity acts on all apples on an apple tree. Some apples are twice as far from the ground as others. These twice ashigh apples, for the same mass, have practically 

Definition
the same weight
F = G M m / d^{2}
Being twice as far above the ground has hardly any effect on d, the distance from the center of Earth to the apple.



Term
The planet Jupiter is about 300 times as massive as Earth, yet on its surface you would weigh only about 3 times as much. This is because 

Definition
Jupiter's radius is 10 times Earth's radius. 


Term

Definition


Term

Definition

