Hello, I need help with the following:

The motion of a spring-mass system is described by the equation y=2sin(pi*t - pi/2) where y is the distance in feet from equilibrium position and t is time in seconds.

a. If the weight is 24 feet from the ceiling in a state of equilibrium, find the starting position of the weight (time=0).

b. Find the position of the mass at 3 seconds.

c. What is the first time the mass will reach equilibrium position?

Thanks