Q- A cart (m₁ = 120 kg) is moving to the right along a track at v_1i = 15 m/s when it hits a stationary cart (m₂ = 360 kg) and rebounds with a speed of v_1f = 7 m/s in the opposite direction.

1. With what speed does the 360 kg cart move after the collision?
2. An observer moves in the same direction as the incoming cart with a speed of 12 m/s. (positive) Using the convention that the positive direction is to the right, what are the velocities of both bodies with respect to this observer before and after collision
3. What is the total momentum of the system before and after the collision as seen by this moving observer?
4. Discuss the results found in c).

Solution