A coin is placed 14.0 cm from the axis of a rotating turntable of variable speed. When the speed of the turntable is slowly increased, the coin remains fixed on the turntable until a rate of 31.0 rpm (revolutions per minute) is reached, at which point the coin slides off.

Question

A coin is placed 14.0 cm from the axis of a rotating turntable of variable speed. When the speed of the turntable is slowly increased, the coin remains fixed on the turntable until a rate of 31.0 rpm (revolutions per minute) is reached, at which point the coin slides off.
Part A
What is the coefficient of static friction between the coin and the turntable?

Scott · Answer

friction force = centripetal force μ m g = m v^2 / r μ = v^2 / (g r)

Anonymous · Answer

What is a wheels velocity if it rotates through 720 degrees every two seconds