1. The problem statement, all variables and given/known data A ball is dropped from a height of 10 meters onto a hard surface so that the collision at the surface may be assumed elastic. Under such conditions the motion of the ball is (A) simple harmonic with a period of about 1.4 s (B) simple harmonic with a period of about 2.8 s (C) simple harmonic with an amplitude of 5 m (D) periodic with a period of about 2.8 s but not simple harmonic (E) motion with constant momentum 3. The attempt at a solution I would assume that since its an elastic collision, that it would engage in simple harmonic motion, but the answer is D so evidently that is not the case. Anyone care to explain?