In an engine, a piston oscillates with simple harmonic motion so that its position varies according to the expression, x = 7.00 cos (31' + E) where x is in centimeters and t is in seconds. (a) At t = 0, find the position of the piston. cm (b) At t = 0, find velocity of the piston. cm/s (c) At t = 0, find acceleration of the piston. cm/s2 (d) Find the period and amplitude of the motion. penod s amplitude cm