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
at the highest position of the platform
at the mean position of the platform
for an amplitude of
or an amplitude of
As we learnt in
Equation of S.H.M. -
- wherein
In vertical simple harmonic motion, maximum acceleration and so the maximum force 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 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.
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