The position of a 030 kilogram object attached to a spring

Question

The position of a 0.30 kilogram object attached to a spring is described by the following equation: x = (0.23 m)cos(0.4t)

(a) Evaluate what the amplitude of the motion.

m

(b) Evaluate what the spring constant.

N/m

(c) Determine the position at t = 0.35 second.

m

(d) Determine the object's speed at t = 0.35 second.

m/s