A cylinder rolls up an inclined plane, reaches some height, and then rolls down (without slipping throughout these motions). The directions of the frictional force acting on the cylinder are.

Options

A. up the incline while ascending and down the incline while descending
B. up the incline while ascending as well as descending .
C. down the incline while ascending and upto the incline while descending
D. down the incline while ascending as well as descending

Answer

b

Explanation

As shown in component of weight `(mg sin theta)` is always down the inclined plane whether the cylinder is rolling up or it is rolling down Therefore for no slipping sense of angular acceleration must be the same in both the cases Therefore force of friction (f) acts up the inclined plane in both the cases
.