HW 22: Momentum Conservation

Instructions: To receive full credit, you must: 1) Draw a picture when possible; 2) Show all steps clearly (GUESS method); and 3) Include correct units on your answer.

1. You are riding down the street on your bike. Which has more momentum, you or the bike? Explain your reasoning.

2. A horse is pulling a cart of grain at a constant speed, but there is a hole in the cart and grain is leaking out.a. Does the momentum of the cart increase, decrease, or stay the same?b. What happens to the kinetic energy of the cart?

3. A 60-kg person is skating on ice at a speed of 2.0 m/s to the right. An 80 kg person is skating to the left at 1.0 m/s towards the first person. What is the total momentum after the two skaters collide?

4. 4. A 10,000-kg railroad car traveling at a speed of 24.0 m/s strikes a 15,000-kg locomotive at rest, as shown. The cars lock together as a result of the collision.a. What type of collision is this?b. What is their common speed vf after the

collision?

5. A 9300-kg boxcar traveling at 15.0 m/s strikes a second boxcar at rest. The two stick together and move off with a speed of 6.0 m/s. What is the mass of the second car?

6. Two carts are approaching each other as shown. Cart 1 is 4.0 kg and has a velocity of 3.0 m/s to the right. Cart 2 has a mass of 6.0 kg and a velocity of 3.0 m/s to the left. After the collision the carts separate and the 6.0 kg cart moves to the right at a velocity of 1.0 m/s.a. What type of collision is this?b. What is the speed and direction of the 4.0-kg cart after the collision?

7. The diagram below shows two carts that were initially at rest on a horizontal, frictionless surface being pushed apart when a compressed spring attached to one of the carts is released. Cart A has a mass of 3.0 kg and cart B has a mass of 5.0 kg.

If the speed of cart A is 0.33 m/s after the spring is released, what is the approximate speed of cart B after the spring is released?

A. 0.12 m/sB. 0.20 m/sC. 0.33 m/s

D. 0.55 m/sAnswersThese answers are provided so that you receive immediate feedback. Use them to check your work and to assess your own understanding. If you don’t 100% understand how to reach these answers, come in for extra help.

4b: 9.6 m/s6b: 3 m/s to the left