Question

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,
(correct answer + 1, wrong answer - 0.25)

• 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 up the incline while descending.
• D. down the incline while ascending as well as descending.

Answer 1

The correct option is B up the incline while ascending as well as descending.

While ascending velocity decreases and friction acts upwards to reduce angular velocity. Similarly, while descending velocity increases and so does angular velocity.