# A coin is placed on a horizontal platform which undergoes vertical simple harmonic motion of angular frequency  The amplitude of oscillation is gradually increased. The coin will leave contact with the platform for the first time Option 1) at the highest position of the platform Option 2) at the mean position of the platform Option 3) for an amplitude of     Option 4) or an amplitude of

As we learnt in

Equation of S.H.M. -

- wherein

In vertical simple harmonic motion, maximum acceleration$\left ( a\omega ^{2} \right )$        and so the maximum force$\left ( ma\omega ^{2} \right )$        will be at extreme positions. At highest position, force will be towards mean position and so it will be downwards. At lowest position, force will be towards mean position and so it will be upwards This is opposite to weight direction of the coin. The coin will leave contact will the platform for the first time when $m\left ( a\omega ^{2} \right )\geq mg$      at the lowest position of the platform.

Correct  option is 3.

Option 1)

at the highest position of the platform

This is an incorrect option.

Option 2)

at the mean position of the platform

This is an incorrect option.

Option 3)

for an amplitude of

This is the correct option.

Option 4)

or an amplitude of

This is an incorrect option.

## Similar Questions

### Preparation Products

##### Knockout JEE Main April 2021 (One Month)

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Weekend Live Classes, Mentorship from our Experts, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 14000/- ₹ 4999/-
##### Knockout JEE Main May 2021

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Weekend Live Classes, Mentorship from our Experts, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 22999/- ₹ 9999/-
##### Test Series JEE Main May 2021

Unlimited Chapter Wise Tests, Unlimited Subject Wise Tests, Unlimited Full Mock Tests, Get Personalized Performance Analysis Report,.

₹ 6999/- ₹ 2999/-
##### Knockout JEE Main May 2022

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Weekend Live Classes, Mentorship from our Experts, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 34999/- ₹ 14999/-