Question

A gramophone record is revolving with angular velocity . 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. $r=\mu g{\omega }^2$
• B. $r<\frac{{\omega }^2}{\mu g}$
• C. $r\le \frac{\mu g}{{\omega }^2}$
• D. $r\ge \frac{\mu g}{{\omega }^2}$

Answer 1

The correct option is C $r\le \frac{\mu g}{{\omega }^2}$