Question

A uniform circular disc of mass $m$ and radius $R$ is rolling on a horizontal surface. Find the angular momentum of the disc about an axis perpendicular to the plane of disc and fixed at point $P$ to the disc.

Answer 1

$L=L_{CM}+Mvr$

$⟹L=I\omega +Mv\frac{R}{2}$

$⟹l=\frac{1}{2}M{R}^2\omega +Mv\frac{R}{2}$

$⟹L=MvR$ since $\omega R=v$