# What is angular momentum?

Apr 16, 2018

Angular momentum is the rotational analogue of the Linear momentum.

#### Explanation:

Angular momentum is denoted by $\vec{L}$.

Definition :-

The instantaneous angular momentum $\vec{L}$ of the particle relative to the origin $O$ is defined as the cross product of the particle’s instantaneous position vector $\vec{r}$and its instantaneous linear momentum $\vec{p}$

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

For a rigid body having fixed axis rotation , the angular momentum is given as $\vec{L} = I \vec{\omega}$ ; where $I$ is the Moment of Inertia of the body about the axis of rotation.

The net torque $\vec{\tau}$ acting on a body is give as the rate of change of Angular Momentum.

$\therefore \sum \vec{\tau} = \frac{\mathrm{dv} e c L}{\mathrm{dt}}$