Consider a collision between two objects of different masses M,m moving in one dimension with initial speeds V, −v. In the center-of-mass frame, the total momentum is zero before and after the collision. In an elastic collision both energy and momentum are conserved. Compute the velocities of the two objects after an elastic collision in the center-of-mass frame. Show that in the limit where m/M → 0, the more massive object remains at rest in the center-of mass frame (V = 0 before and after the collision), and the less massive object simply bounces off the more massive object (like a tennis ball off a concrete wall).