You observe an object on a spring to oscillate with an angular frequency of 4π radians per second, and to

reach a maximum displacement from its equilibrium point of 0.75 meters.

(a) What is the maximum velocity of the object?

(b) If the spring constant k = 150 N/m, what is the mass of the object?

(c) What is the speed of the object when it is displaced 0.20 meters from the equilibrium point?