The gravitational PE of an object is proportional to

1. The gravitational PE of an object is proportional to • A. The object’s mass and its speed • B. The object’s speed and its height • C. The object’s mass and its height • D. The object’s mass and the square of its speed Answer: C

2. A ball is thrown straight upward. At the top of the ball’s flight, • A. The ball’s kinetic energy is at its maximum value. • B. The ball’s PE is at its minimum value • C. The ball’s PE is equal to its KE • D. The ball’s KE is zero Answer: D

3. The energy stored in a stretched rubber band is an example of • A. Gravitational PE • B. Elastic PE • C. Kinetic Energy • D. Heat Energy Answer: B

4. Mechanical Energy is: • A. The sum of all energies • B. The sum of KE and PE • C. The product of all energies • D. The product of KE and PE Answer: B

5. During the summer, Janice mows the lawn every week. While she is pushing the lawn mower, which of the following forces does negative work on the mower? A. The force of gravity B. The upward force of the ground C. The force of friction D. The force of Janice pushing the mower. Answer: C

6. The period of a simple pendulum depends on its • A. Mass • B. Length • C. Total Energy • D. Velocity at the central position Answer: B

7. What is the amount of work done by the force shown in this force-displacement graph? F(N) A. 16 J B. 35 J C. 54 J D. 77 J 35 N d(m) 2.2 m Answer: D

8. Two spheres roll across the floor. Sphere A moves twice as fast as sphere B, and sphere A has half the mass of sphere B. The KE of sphere A is Answer: A A. Twice the KE of sphere B B. The same as the KE of sphere C. Half the KE of sphere B D. Four times the KE of sphere B

9. You throw a stone horizontally from a bridge, and it falls toward the river 10 m below. Which of the following quantities increases during the first second after you release the stone? A. The elastic PE of the stone B. The KE of the stone C. The gravitational PE of the stone D. The Total Mechanical energy of the stone Answer: B

10. Using ground level as the reference level, the gravitational PE of a ball held at a height of 6.0 meter is 12 J. The ball is dropped from that height and falls toward the ground. After the ball has fallen 4.5 m, its KE is • A. 3 J • B. 6 J • C. 9 J • D. 12 J Answer: C

11. You lift a bag of onions with a mass of 1.4 kg from the floor to a shelf in the cupboard 1.7 m above the floor. What is the change in the gravitational PE of the bag of onions? • A. 2.4 J • B. 3.1 J • C. 12 J • D. 23 J Answer: D

12. Joseph uses a rope to pull a concrete block across the floor. He holds the rope at an angle of 250with the floor and uses a force of 350 N to pull the block 7.5 m. How much work is done on the block? • A. 188 J • B. 2.4 kJ • C. 2.6 kJ • D. 8.8 kJ Answer: B

13. A spring with an elastic constant of 196 N/m oscillates up and down with a 1.00 kg mass attached to it. Its period will be approximately • A. 0.032 sec • B. 0.071 sec • C. 0.45 sec • D. 4.5 sec Answer: C

14. A 1 kg ball starts from rest and rolls down a frictionless inclined plane that is 2.5 m long and 1.4 m high. What is the ball’s speed when it reaches the bottom of the incline? • A. 3.7 m/s • B. 5.2 m/s • C. 7.0 m/s • D. 8.5 m/s Answer: B

15. When a 1.00 kg MASS is suspended from a spring, the spring stretches by 0.050 meters. The elastic constant for this spring is • A. 0.20 N/m • B. 1.96 N/m • C. 49 N/m • D. 196 N/m Answer: D