Question

As shown in the figure, a uniform disc of mass $m$ is rolling without slipping with a angular velocity. The portion $AB$ is rough and $BC$ is smooth. When it crosses point $B$ disc will be in:

• A. translational motion only
• B. pure rolling motion
• C. rotational motion only
• D. None of the above

Answer 1

The correct option is A translational motion only

Since the body is rolling on the rough surface, friction does not act.

On the smooth surface, Since no external torque, and forces are present , it continuous to roll. Hence only translational motions is present.