Why is angular momentum perpendicular?

1 Answer
Aug 7, 2015

Angular momentum as you can tell from its name is related to the rotation of an object or a system of particles.


Having said that, we have to forget all about the linear and translational motion that we are so familiar with. Therefore, angular momentum is simply a quantity that shows rotation.


Look at the little curved arrow which shows angular velocity (likewise with angular momentum).

  • The Formula *

We have a cross product for the 2 vectors which shows that angular momentum is perpendicular to the radial vector, #vecr# and velocity vector #vecV#. If #vecL# points up in your right hand rule, the direction is anti-clockwise and vice-versa.