8.3 Exercise 3

A student sets up an experiment to measure the momentum of a system of two air cars, A and B, of equal mass, moving on a linear, frictionless track. Before the collision, car A has a certain speed, and car B is at rest. Which of the following will be true about the total momentum of the two cars?

1. It will be greater before the collision.
2. It will be equal before and after the collision.
3. It will be greater after the collision.
4. The answer depends on whether the collision is elastic or inelastic.