A mass is on a piston that oscillates vertically describing a S.H.M. T= 1s.

1-At which amplitude does the mass comes off the piston?

The answer is supposed to be 25 cm but I don't know how to find the position of the mass when it comes off the piston. I found w but I couldn't write the equation.

2- If the amplitude was 5 cm, what would be the maximum frequency so that the mass remains on the piston?

The answer is f=2,24 Hz