Please answer ALL questions.

1. Two balls of identical mass and composition are resting on a smooth floor. Both balls are pushed. One ball travels 5 meters and the other travels 10 meters. What can you say about the force applied to the balls?

a. The ball that traveled 10 meters must have been pushed with more force than the ball that traveled 5 meters.

b. The ball that traveled 5 meters must have been pushed with more force than the ball that traveled 10 meters.

c. Both balls must have been pushed with the same amount of force because they have the same mass.

2. Which of the following is an example of work being done? There could be more than one correct answer.

a. A ball being rolled on the floor.

b. A student carrying a backpack up the stairs.

c. Keys hanging from a key chain.

d. A weightlifter carrying weights on his shoulders across flat ground.

e. A book resting on a desk.

f. A professor sitting in a chair.

3. Order the following systems according to their kinetic energy, least to greatest: A) a car driving down a hill. B) a person running down a hill. C) a ball rolling down a hill. D) leaves rolling down a hill

a. A, B, C, D

b. C, D, B, A

c. B, A, C, D

d. D, C, B, A

4. If a cheetah with a mass of 50 kg runs at a speed of 28 m/s, what is the cheetah's kinetic energy?

a. None of the given choices are correct.

b. 1,400 J

c. 700 J

d. 39,200 J

e. 19.6 kJ

5. A 22-kg moving object has a kinetic energy of 135 J. The object's speed is about:

a. 3.5 m/s

b. 6.1 m/s

c. 12.3 m/s

d. 2.5 m/s

6. Order the following systems in order of their gravitational potential energy, least to greatest:

A) a ball sitting on the ground

B) a submarine 100 m below the surface of the ocean

C) an airplane flying 10,000 m above the ground

D) a rock sitting on top of Mt. Everest (8,850 m high)

a. A, B, C, D

b. B, A, D, C

c. C, D, A, B

d. A, B, D, C

7. To increase the gravitational potential energy of an object without changing its mass, you could:

A) Make the object wider

B) Lower the object toward the ground

C) Raise the object farther off the ground

D) Allow the object to roll on the ground

a. B only

b. D only

c. either A or C

d. either B or D

e. either C or D

f. C only

g. A only

h. either A, C, or D

8. The gravitational potential energy of a 7 kg object at a height of 12 m above the ground is about:

a. 84 J

b. 823 J

c. 2,688 J

d. 1.7 J

9. A 16-kg rock rests on a boulder 25 m above the ground on a distant planet. If the rock's gravitational potential energy is 1.48 kJ, the planet's acceleration due to gravity is about:

a. 16 m/s²

b. 5.9 m/s²

c. 3.7 m/s²

d. 0.0037 m/s²

10. An object is 428 m above the ground. If the object's gravitational potential energy is 920 J, the mass of the object is about:

a. 94 kg

b. 394 kg

c. 219 g

d. 219 kg

e. 2.15 kg

11. A spring stretches 20 cm when a mass of 3kg is hung from it. What is its spring constant?

a. 147 N/m

b. 0.15 N/m

c. 15 N/m

d. 1.47 N/m

12. The spring constant of a spring is 30 N/m. What force is required to compress it 0.5 m?

a. 15 N

b. 30 N

c. 1.5 N

d. 60 N

13. Elasticity of an object is:

a. a property that prevents it from returning to its original shape after being distorted.

b. measured by its stickiness.

c. the maximum amount the object can be stretched.

d. its property to return to its original shape after being distorted.

14. Order the springs from the most stiff to the least stiff:

Spring A: needs 100 J of work to compress it by 0.2 m

Spring B: needs 180 J of work to stretch it by 0.3 m

Spring C: needs 270 J of work to stretch it by 0.5 m

a. C, A, B

b. B, A, C

c. A, B, C

d. C, B, A

e. A, C, B

15. What happens when a falling object hits the ground?

a. Kinetic energy is converted to gravitational potential energy.

b. Energy is destroyed.

c. Kinetic energy is converted to heat and sound, which may cause the object to deform or fracture.

16. Gravitational potential energy depends on an object's mass and ["acceleration", "speed", "height"].

17. Kinetic energy of an object depends on its mass and ["speed", "height"].

18. When an object falls:

a. kinetic energy is converted to gravitational potential energy

b. gravitational potential energy is converted to kinetic energy

19. In the simulation below, you can watch the kinetic energy of a skater being converted to gravitational potential energy. Click on this link:https://phet.colorado.edu/en/simulation/energy-skate-park-basics.

Once the link opens, click on the arrow to run the simulation. When a new window opens, choose the Introduction.Selectthe boxes for "bar graph" and "speed" so you can watch the change in speed of the skater and the energy transformations that happen. With theU-shaped track selected, click and drag the skater onto the track. Let him go and watch the changesofkinetic andpotential energy that occur as the skater moves up and down the track. Also observe the speeds. You can run everything in slow motion. Answer the following questions.

The skater's speed is maximum ["in the middle", "at the bottom", "at the top"] of the track.

The skater's ["potential energy", "kinetic energy", "speed"] is maximum at the top of the track.

The skater's total energyis ["minimum at the top of", "constant everywhere along", "maximum at the top of"] the track.

20. At which point(s) on the roller coaster is the kinetic energy at its maximum?

\f6 m/s 3 m/s 7 kg 5 kg B) A) 9 m/s 15 kg 3 kg D) 2 m/s C)A B C