Question

A cylinder rolls up an inclined plane reaches a certain height and then goes down without slipping through these motions the direction of the frictional force acting on the slender

Answer 1

the force of friction is always opposite to the direction of motion... when the cylinder rolls up the force of friction is directed downwards ..and when the cylinder slips down the force of friction acts upwards..

so.. the force of friction is always opposite to the direction of motion and tangential to the normal reaction...