Question

Which graph describes motion of point $P$ on the disc, initially at origin?

• A.
• B.
• C.
• D. $\text{None of these}$

Answer 1

The correct option is C

Motion of point $P$ with respect to the center of mass is pure rotational while center of mass itself is moving in a straight line. So for the analysis of rolling motion, we deal translational motion and rotational motion separately and then we combine
the results to analyse the overall general motion.
Analysing both motion gives an approximate graph of point $P$ as

Maximum $y-$ coordinate of point $P$ will be $2r$ where, $r$ is the radius of wheel.