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A gramphone record is revolving with an ...

A gramphone record is revolving with an angular velocity omega. A coin is placed at a distance `r` from the centre of the record. The static coefficient of friction is mu. The coin will revolve with the record if.

A

`r ge (mu g)/(omega^(2))`

B

`r = mu g omega^(2)`

C

`r lt (omega^(2))/(mu g)`

D

`r le (mu g)/(omega^(2))`

Text Solution

Verified by Experts

The correct Answer is:
D
Since , `v le sqrt(mu r g)`
`implies v^(2) le mu r g`
`implies (r omega)^(2) = mu r g`
`implies r omega^(2) le mu g implies r le (mu g)/(omega^(2))`
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