Question

A ball rolling down a rough inclined plane. Name the contact force which is acting on the ball

Answer 1

The forces of gravity and friction work together to create the rotation of the ball from the inclined surface and the difference in apparent torque arrives as the fact that it works in different frame of reference.

If there were no friction then the ball will not easily roll out. When there is friction, the force of gravity serves as center of mass & there is no torque.

Answer 2

Force of friction is the answer