Answer:
5.5 rad/s
Explanation:
The friction between the coin and the turntable provides the centripetal force that keeps the coin in circular motion. Therefore, we can write:
where
is the coefficient of friction
m is the mass of the coin
is the acceleration of gravity
is the angular speed
r is the distance of the coin from the centre of rotation
In this problem,
r = 11.0 cm = 0.11 m
The coin starts to slip when the centripetal force becomes larger than the maximum frictional force:
Solving for , we find the angular speed at which this happens: