A coin of 5.30 gram is placed 12.0 cm from the center of a turntable. The coin has static and kinetic coefficients of friction with the turntable surface of = 0.900 and = 0.470.

Question

A coin of 5.30 gram  is placed 12.0 cm from the center of a turntable. The coin has static and kinetic coefficients of friction with the turntable surface of  = 0.900 and  = 0.470.
What is the maximum angular velocity with which the turntable can spin without the coin sliding?

drwls · Accepted Answer

The static friction coefficient, Us, determines when it starts sliding. M*g*Us = M*R*w^2 Solve for w, the angular velocity. w = sqrt(g*Us/R) = 8.57 rad/s