A 1.2kg block sliding on a horizontal frictionless surface is attached to a horizontal spring with k = 480 N ∙ m. Let x be the displacement of the block from the position at which the spring is un-stretched. At t = 0 the block passes through x = 0 with a speed of 5.2 m/s in the positive x direction. What are the
(a) Frequency and
(b) Amplitude of the block's motion?
(c) Write an expression for x as a function of time.