Angular Momentum

Angular momentum is related to linear momentum in that it measures the amount of motion in a body. Linear momentum measures the amount of linear motion, while angular momentum measures the amount of angular motion.

The equation for linear momentum (p) is mass (m) times velocity (v), while for angular momentum (L) it is moment of inertia (I) times angular velocity (w) (makes you wonder if mass = inertia?). Since nothing is ever at rest because there is no absolute zero-motion reference frame (as far as we know), everything has momentum, both linear and angular.

Equations that show the relationship between linear and angular momentum:

linear momentum = m*v

angular momentum = I*w

force = m*a

torque = I*w

linear kinetic energy = ½mv²

angular kinetic energy = ½I*w²