AP Physics Energy
John's mass is half the mass of Jill. They both start walking and John moves twice as fast as Jill. What is the ratio of the kinetic energy of Jill to the kinetic energy of John? Select one: a. 2 b. 1/2 c. 4 d. 1/8 e. 1
b
A lightweight object and a very heavy object are sliding with equal speeds along a level frictionless surface. They both slide up the same frictionless hill. Which rises to a greater height? Select one: a. They both slide to the same height. b. The lightweight object, because it weighs less. c. The heavy object, because it has greater kinetic energy. d. cannot be determined from the information given
a
Car J moves twice as fast as car K, and car J has half the mass of car K. The kinetic energy of car J, compared to car K is Select one: a. 2 to 1. b. 4 to 1. c. the same. d. 1 to 2.
a
If the net work done on an object is positive, then the object's kinetic energy Select one: a. increases. b. is zero. c. remains the same. d. decreases
a
If the net work done on an object is zero, then the object's kinetic energy Select one: a. remains the same. b. increases. c. is zero. d. decreases.
a
In the SI system of units, power has the same units as Select one: a. Nm/s. b. W/m. c. W/s. d. Jm/s. e. Js/m.
a
A 0.200-kg mass attached to the end of a spring causes it to stretch 5.0 cm. If another 0.200-kg mass is added to the spring, the potential energy of the spring will be Select one: a. the same. b. 4 times as much. c. 3 times as much. d. twice as much
b
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? Select one: a. K is equal to U. b. K is less than U. c. K is greater than U. d. It is impossible to tell.
b
If you walk 5.0 m horizontally forward at a constant velocity carrying a 10-N object, the amount of work you do is Select one: a. less than 50 J, but more than 0 J. b. zero. c. more than 50 J. d. equal to 50 J
b
King Kong falls from the top of the Empire State Building, through the air (air friction is present), to the ground below. How does his kinetic energy (K) just before striking the ground compare to his potential energy (U) at the top of the building? Select one: a. K is greater than U. b. K is less than U. c. K is equal to U. d. It is impossible to tell.
b
Two inclined planes A and B have the same height but different angles of inclination with the horizontal. An object is released at rest from the top of each of the inclined planes. How does the speed of the object at the bottom of inclined plane A compare with that of the speed at the bottom of inclined plane B? Select one: a. It is directly proportional to the angle. b. It is same for both planes. c. It is inversely proportional to the angle. d. There is not enough information to answer the question.
b
A 4.0 kg mass is moving with speed 2.0 m/s. A 1.0 kg mass is moving with speed 4.0 m/s. Both objects encounter the same constant braking force, and are brought to rest. Which object travels the greater distance before stopping? Select one: a. the 4.0 kg mass b. the 1.0 kg mass c. Both travel the same distance. d. Cannot be determined from the information given.
c
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? Select one: a. 2 b. 4 c. 1/4 d. 1/2
c
Block 1 and block 2 have the same mass, m, and are released from the top of two inclined planes of the same height making 30° and 60° angles with the horizontal direction, respectively. If the coefficient of friction is the same in both cases, which of the blocks is going faster when it reaches the bottom of its respective incline? Select one: a. We must know the actual masses of the blocks to answer. b. Both blocks have the same speed at the bottom. c. Block 2 is faster. d. Block 1 is faster. e. There is not enough information to answer the question.
c
If the net work done on an object is negative, then the object's kinetic energy Select one: a. increases. b. is zero. c. decreases. d. remains the same
c
Two identical vertical springs S1 and S2 have masses m1 = 400 g and m2 = 800 g attached to them. If m1 causes spring S1 to stretch by 4 cm, what is the ratio of the potential energy of S1 and S1? Use g = 10 m/s2. Select one: a. 4:1 b. 1:2 c. 1:4 d. 2:1 e. 1:3
c
A container of water is lifted vertically 3.0 m then returned to its original position. If the total weight is 30 N, how much work was done? Select one: a. 90 J b. 180 J c. 45 J d. No work was done.
d
A person carries a mass of 10 kg and walks along the +x-axis for a distance of 100 m with a constant velocity of 2 m/s. What is the work done by this person? Select one: a. 20 J b. 200 J c. 1000 J d. 0 J e. None of the other choices is correct.
d
If you walk 5.0 m horizontally forward at a constant velocity carrying a 10 N object, the amount of work you do is Select one: a. more than 50 J. b. equal to 50 J. c. less than 50 J, but more than 0 J. d. zero.
d
What is the correct unit of power expressed in SI units? Select one: a. kg m2/s2 b. kg m/s2 c. kg2 m/s2 d. kg m2/s3
d
A simple pendulum, consisting of a mass m and a string of length L, swings upward, making an angle q¸ with the vertical. The work done by the tension force is Select one: a. mgL. b. mgL tan q¸. c. mgL sin q¸. d. mgL cos q¸. e. zero.
e
Two identical balls are thrown from the top of a building with the same speed. Ball 1 is thrown horizontally, while ball 2 is thrown at an angle q¸ above the horizontal. Neglecting air resistance, which ball will have the greatest speed when hitting the ground below? Select one: a. Ball 1 b. Ball 2 c. Cannot be determined without knowing the time each ball is in the air. d. Cannot be determined without knowing the height of the building. e. Both balls reach the ground with the same speed.
e
Work done by STATIC FRICTION is always Select one: a. parallel to the surface. b. perpendicular to the surface. c. negative. d. positive. e. zero.
e