$A$ particle of mass $0.5\, kg$ is rotating in a circular path of radius $2\, m$ and centripetal force on it is $9\, N$. Its angular momentum (in $J\cdot s$) is:

Write the $SI$ unit of angular momentum and its dimensional formula.

Show that the angular momentum about any point of a single particle moving with constant velocity remains constant throughout the motion.

When a mass moves in a plane about a fixed point,the direction of its angular momentum is along which of the following?

$A$ disc of mass $M$ and radius $R$ is rolling on a horizontal surface as shown in the figure. What is the magnitude of the angular momentum of the disc about the origin $O$?

$A$ solid cylinder of mass $20 \ kg$ rotates about its axis with an angular speed of $100 \ rad \cdot s^{-1}$. The radius of the cylinder is $0.25 \ m$. The magnitude of its angular momentum about the axis of the cylinder is ........ $J \cdot s$.