Angular Momentum

Angular Momentum is the angular analogue of Linear Momentum. The formulas are very similar to torque.

Angular momentum about the pivot at $O$ is

${\vec{L}}_O=\vec{r}\times \vec{p}$

where $\vec{p}=m\vec{v}$ is the Linear Momentum

The magnitude of the angular momentum is thus given by $L_O=rp\sin \theta$

We can also describe angular momentum in terms of angular speed, where $L_O=I_0\vec{w}$

Conservation of Angular Momentum

The principle of conservation of angular momentum states that in the absence of a net external torque, the angular momentum will not change.