A coin of mass m is placed a distance r from the centre of a turntable

A coin of mass m is placed a distance r from the centre of a turntable. The coefficient of static friction between the coin and the turntable is μ. Starting from rest, the turntable is gradually rotated faster and faster. At what angular velocity does the coin slip from its position?
What direction does the static friction force point?
Explain your answer.