NEET2017PhysicsRotational MotionActual
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
- Aup the incline while ascending and down the incline while descending.
- Bup the incline while ascending as well as descending.
- Cdown the incline while ascending and up the incline while descending.
- Ddown the incline while ascending as well as descending.
Correct answer
B. up the incline while ascending as well as descending.
Step-by-step solution
See given the figure. It is obvious from figure, that during ascending, a retarding, i.e. anticlockwise moment is required. It should be remembered that torque due to friction has the same sense the angular acceleration.