Answer:
in the downward movement of the movement when the constant is lost
Step-by-step explanation:
When the coin is on the piston it has a relationship given by
a = d²x / dt²
the piston position is
x = A cos wt
a = - A w² cos wt
the maximum acceleration is
a = - A w²
When the piston raises the acceleration of gravity and that of the piston go in the same direction, when the piston descends they relate it is contrary to gravity, therefore when the frequency increases, the point where the acceleration of the piston is greater than gravity arrives and the coin loses contact.
The point where you lose contact is
a = g
g = A w²
In short, in the downward movement of the movement when the constant is lost