Question

1. In a traffic collision, a car runs into the back of another car. The first car comes to a stop and then the other slides for a bit before coming to rest. What kind of collision is this? Is momentum conserved in the system? Is kinetic energy conserved? Explain your reasoning for full points.

2. Cart one sits still on a track that is 1 meter higher than another track. Cart two is on the lower track and moves with velocity 1.3 m/s. Both have the same mass of “m.” What are their total energies, including kinetic and gravitational potential? Remember to define your 0 potential point somewhere. Without changing their velocities, how would you make their total energies equal?

3. Cart one and cart two sit on the same frictionless track, and move toward each other with the same velocity. Both have the same mass of “m.” When they collide, an explosive charge is set off. What is the total momentum before and after the collision? Was momentum conserved in the system? Why or why not?

4. A cart is found to be rolling 2 m/s at the bottom of a frictionless track. How high above the bottom of the track was it released from rest?

Answer 1

In the question 1 , friction is present there so kinetic energy and momentum will not conserve.