Question

A uniform rod of mass $m$ is rotated about an axis passing through point $O$ as shown. Find angular
momentum of the rod about rotational axis.

Answer 1

$I=\frac{m(3l{)}^2}{12}+m{\left(\frac{l}{2}\right)}^2=m{l}^2$
$L=I\omega =m{l}^2\omega$