NEET2010PhysicsLaws of MotionActual
A gramophone record is revolving with an angular velocity . A coin is placed at a distance r from the centre of the record. The static coefficient of friction is . The coin will revolve with the record if
Options
- Ar = g ^2
- Br < ^2 g
- Cr g ^2
- Dr g ^2
Correct answer
C. r g ^2
Step-by-step solution
When the disc spins the frictional force between the gramophone record and coin is mg The coin will revolve with record, if aligned F_ frictional & F_ centripetal m g & m ^2 r g r & ^2 aligned