A 9.15 kg object on a horizontal frictionless surface is attached to a spring with k = 2350 N/m. The object is displaced from equilibrium 73.8 cm horizontally and given an initial velocity of 14.8 m/s back toward the equilibrium position. What are
(a) the motion's frequency (in Hz),
(b) the initial potential energy of the block-spring system,
(c) the initial kinetic energy, and
(d) the motion's amplitude?