Consider a system to be two train cars traveling toward each other. What is the total momentum of the system before the train cars collide? kg • m/s What must the total momentum of the system be after the train cars collide? kg • m/s.

Asap and show ! a 14 kg rock starting from rest free falls through a distance of 5.0 m with no air resistance. find the momentum change of the rock caused by its fall and the resulting change in the magnitude of earths velocity. earth mass is 6.0 * 10^24 kg. show your work assuming the rock earth system is closed.