Laws of Motion

Question

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

  • Up the incline, while ascending and down the incline while descending

  • Up the incline, while ascending as well as descending

  • down the incline, while ascending and up the incline while descending

  • Down the incline while ascending as well as descending.

Answer

B.

Up the incline, while ascending as well as descending

It is obvious that during ascending, a retarding i.e. anticlockwise moment is required. I should be remembered that torque due to friction has the same sense the angular acceleration.

Sponsor Area