PHY-102: Energy and Circular Motion Exercises

Complete the following exercises.

1.A rifle with a longer barrel can fire bullets with a larger velocity than a rifle with a shorter barrel.

a. Explain this using the impulse-momentum theorem.

b. Explain this using the work-energy theorem

2.Use physics terms to explain the benefits of crumple zones in modern cars.

3.When a gun is fired at the shooting range, the gun recoils (moves backward). Explain this using the law of conservation of momentum.

4.Rank the following in terms of increasing inertia:

A.A 10,000 kg train car at rest

B.A 100 kg person running at 5 m/s

C.A 1200 kg car going 15 m/s

D.A 15 kg meteor going at a speed of 1000 m/s

5.Rank the following in terms of increasing momentum:

A.A 10,000 kg train car at rest

B.A 100 kg person running at 5 m/s

C.A 1200 kg car going 15 m/s

D.A 15 kg meteor going at a speed of 1000 m/s

6.Rank the following in terms of increasing kinetic energy:

A.A 1200 kg car going 15 m/s

B.A 10,000 kg train car at rest

C.A 15 kg meteor going at a speed of 1000 m/s

D.A 100 kg person running at 5 m/s

7.Ben (55 kg) is standing on very slippery ice when Junior (25 kg) bumps into him. Junior was moving at a speed of 8 m/s before the collision and Ben and Junior embrace after the collision. Find the speed of Ben and Junior as they move across the ice after the collision. Give the answer in m/s. Describe the work you did to get the answer