1.6 Consider a head-on, elastic collision between two bodies whose masses are m and M, with m < M. It is well known that if m has speed vo and M is initially at rest, m will bounce straight back with its speed unchanged, while M will remain at rest (to an excellent approximation). Use this fact to predict the final velocities if M approaches with speed vo and m is initially at rest. [HINT: Consider the reference frame attached to M.]