Ablock of mass m is undergoing shm on a horizontal, frictionless surface while attached to a light, horizontal spring. the spring has force constant k, and the amplitude of the shm is a. the block has v = 0, and x = +a at t = 0. it first reaches x = 0 when t=t/4, where t is the period of the motion.

a) in terms of t, what is the time t when the block first reaches x=a/2?

b)the block has its maximum speed when t=t/4. what is the value of t when the speed of the block first reaches the value vmax/2?

c)(hidden. will ask in comments)