A truck of 4000 Kg mass and tom length Its center of mass 4 m behind the start of It where we put weight of 1400 xg so that the center of mass will be right the middle of the truck.

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 • what must the total momentum of the system be after the train cars collide?   kg •