A coin is placed on a horizontal platform which under goes vertical simple harmonic motion of angular frequency `omega`. The amplitude of oscillation is gradually increased. The coin will leave contact with platform for the first time :

Options

A. at the mean position of platform
B. for an amplitude `g//omega^(2)`
C. for an amplitude of `g^(2)//omega^(2)`
D. at the highest position of the platform.

Answer

D

Explanation

At extreme position acceleration is maximum `a_("max")=r omega^(2)`. So the coin will leave the platform for the first time at extreme position only when amplitude is increased.
Thus correct choice is (d).