I have newly begun to study about the role of friction in circular motion and it has beginning to confuse me that when does friction act as a centripetal force and when does it act as a tangential force.
I know that in the case of a car in circular motion, the friction acts a centrifugal force as the car has the tendency to skid from the path if the friction is absent.
However if we keep a collar/ring, on a circular path and move it, the friction acts tangentially backwards.
My argument as to why this happens: The collar/ring is constrained to move in a circular path, therefore it does not need frictional force to act as a centripetal force to keep it moving in the circle. Hence, in this case the component on Normal force acting on the plane of the circular path acts as the centripetal force here instead of friction.
Is my argument correct?