Question 670: Centre of Mass and Rotational Motion

Question

A gramophone 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

Accepted Answer

The coin will revolve with the record, if
Force of friction $$ \ge $$ Centrifugal force
$$\mu mg \ge mr{\omega ^2}$$
$$ \Rightarrow r \le {{\mu g} \over {{\omega ^2}}}$$

Answer

r = $$\mu $$g$$\omega $$2

Answer

r < $${{{\omega ^2}} \over {\mu g}}$$

Answer

$$r \le {{\mu g} \over {{\omega ^2}}}$$

Answer

$$r \ge {{\mu g} \over {{\omega ^2}}}$$

Centre of Mass and Rotational Motion

A gramophone 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

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