A cylinder is pure rolling up an inclined place. It stops momentarily and the rolls back. In what directions is the force of friction directed during the journey?
The Attempt at a Solution
While going up, the cylinder rotates in the anticlockwise direction, and so the friction acts up the plane. On the other hand, while rolling down, the cylinder rotates clockwise, and so the friction acts downward.
Which of those statements is wrong and why?
(As I started thinking, another query arose in my mind; since it is pure rolling, shouldn't the only friction be static friction? And so should that even have a direction?)