Physics Quiz 3 Practice

A student first dives off a platform 5.0 m above the water. Next she dives off a platform 10.0 m above the water. How does her kinetic energy (just as she strikes the water) compare in each dive? a. her kinetic energy is twice as much in the second dive. b. her kinetic energy is one half as much in the second dive. c. her kinetic energy is four times as much in the second dive. d. her kinetic energy is one quarter as much in the second dive. e. her kinetic energy is the same in each dive.

a. her kinetic energy is twice as much in the second dive.

A box fell from a moving truck and quickly skidded to a stop. While the box was moving it had kinetic energy, but when it stopped its kinetic energy was zero. Is this a violation of the law of conservation of energy? a. no, because all the kinetic energy of the box was converted to other types of energy. b. yes, because all the kinetic energy of the box was destroyed. c. We need to know the work done on the box to stop it. d. Maybe, depending on the amount of kinetic energy converted to other types of energy. e. We need to know the value of kinetic energy before the box stopped.

a. no, because all the kinetic energy of the box was converted to other types of energy.

A car and a truck are traveling in the same direction along a road. The truck has twice the mass of the car, but the car has twice the velocity of the truck. How does the magnitude of the linear momentum of each vehicle compare? a. the linear momentum of both vehicles is equal. b. the value of mass and velocity for each vehicle is needed to determine the answer. c. the linear momentum of the car is four times that of the truck. d. the linear momentum of the truck is twice that of the car. e. the linear momentum of the car is twice that of the truck.

a. the linear momentum of both vehicles is equal.

If air resistance and other types of friction can be ignored, the gravitational potential energy of a falling object will a. remain constant. b. be converted into kinetic energy. c. always decrease to a negative value. d. be destroyed. e. increase.

b. be converted into kinetic energy.

Three students determine the gravitational potential energy of an object at a given location. Student A says the gravitational potential energy is positive in value, student B says it is zero in value, and student C says it is negative in value. Which of these students can be correct? a. only student C. b. only student B. c. all of the students. d. only student A. e. either student A or B, but not student C.

c. all of the students.

The brakes on a car do work on the car to slow it down. The work done on the car by the brakes is a. either positive or negative, depending on the original direction of the car's motion. b. only zero in value if the car comes to a complete stop. c. always positive in value d. always negative in value e. always zero in value

d. always negative in value

Two electric motors, A and B are used to do work. The power of motor A is twice that of motor B. Which of the following statements is/are true? a. both motor A can do twice as much work as motor B in twice the amount of time, and motor A can do twice as much work as motor B in the same amount of time. b. motor A can do the same amount of work as motor B in half the amount of time. c. motor A can do twice as much work as motor B in the same amount of time. d. both motor A can do twice as much work as motor B in the same amount of time, and motor A can do the same amount of work as motor B in half the amount of time. e. motor A can do twice as much work as motor B in twice the amount of time.

d. both motor A can do twice as much work as motor B in the same amount of time, and motor A can do the same amount of work as motor B in half the amount of time.

A student attempted to push his stalled car by exerting a force of 1000 N on it, but was unable to move the car. Did the student do work on the car in this case? a. yes b. maybe, depending on the direction of the mass of the car. c. maybe, depending on the amount of time the force was exerted. d. no e. maybe, depending on the direction of the force exerted.

d. no

A baseball is thrown upwards and falls back down again. If air resistance and other types of friction can be ignored, the sum of its gravitational potential energy and kinetic energy will a. increase on the way up, and increase on the way down. b. decrease on the way up, and increase on the way down. c. increase on the way up, and decrease on the way down. d. remain constant on the way up, and remain constant on the way down. e. decrease on the way up, and decrease on the way down.

d. remain constant on the way up, and remain constant on the way down.

A car and a truck are traveling in the same direction along a road. The truck has twice the mass of the car, but the car has twice the velocity of the truck. How does the magnitude of the kinetic energy of each vehicle compare? a. the value of mass and speed for each vehicle is needed to determine the answer. b. the kinetic energy of the truck is twice that of the car. c. the kinetic energy of the car is four times that of the truck. d. the kinetic energy of the car is twice that of the truck. e. the kinetic energy of both vehicles is equal.

d. the kinetic energy of the car is twice that of the truck.

How can a satellite in orbit about the Earth increase its linear momentum, but keep its angular momentum constant? a. increase its speed of orbit and increase its radius of orbit. b. increase its speed of orbit while keeping its radius of orbit constant. c. decrease its speed of orbit and increase its radius of orbit. d. decrease its speed of orbit while keeping its radius of orbit constant. e. increase its speed of orbit and decrease its radius of orbit.

e. increase its speed of orbit and decrease its radius of orbit.

Which statement is always true about an inelastic collision? a. linear momentum is not conserved, kinetic energy is not conserved. b. linear momentum is not conserved, kinetic energy is conserved. c. either linear momentum is conserved, kinetic energy is not conserved; or linear momentum is not conserved, kinetic energy is not conserved, could be true depending on the speed of the objects before and after the collision. d. linear momentum is conserved, kinetic energy is conserved. e. linear momentum is conserved, kinetic energy is not conserved.

e. linear momentum is conserved, kinetic energy is not conserved.

Two boxes, A and B are lifted above the floor. The mass of box A is twice that of box B, but box B is lifted to a height twice that of box A. How does the gravitational potential energy of each box compare? a. the gravitational potential energy of box A is 9.8 times that of box B. b. the gravitational potential energy of box B is 9.8 times that of box A. c. the gravitational potential energy of box B is twice that of box A. d. the gravitational potential energy of box A is twice that of box B. e. the gravitational potential energy of both boxes is equal.

e. the gravitational potential energy of both boxes is equal.

A car and truck are traveling with the same speed along a road. If the truck's mass is twice that of the car, how do their kinetic energies compare? a. the kinetic energy of the truck is one half that of the car. b. the kinetic energy of both vehicles is equal c. the kinetic energy of the truck is four times that of the car. d. the value of mass and speed for each vehicle is needed to determine the answer. e. the kinetic energy of the truck is twice that of the car.

e. the kinetic energy of the truck is twice that of the car.

Two football players run toward each other and collide. The large player was running slowly, while the small player was running quickly just before the collision. Upon colliding they stuck together and immediately 'stopped in their tracks'. How did the magnitudes of the linear momentum of each player compare before the collision? a. none of the choices. b. the linear momentum of the smaller player was greater than that of the larger player. c. the linear momentum of the larger player was greater than that of the smaller player. d. the linear momentum of each player was zero before the collision. e. the linear momentum of both players was equal.

e. the linear momentum of both players was equal.