A block rides on a piston (a squat cylindrical piece) that is moving vertically with simple harmonic motion

A block rides on a piston (a squat cylindrical piece) that is moving vertically with simple harmonic motion.
(a) If the SHM has period 1.0 s, at what amplitude of motion will the block and piston separate?
(b) If the piston has an amplitude of 5.0 cm, what is the maximum frequency for which the block and piston will be in contact continuously?