Angular Momentum

• Angular momentum is the rotational equivalent of linear momentum. It is defined in a similar way, using the rotational analogs to mass and velocity:

              ang mom  L  =  (moment of inertia) * (angular velocity)
  

• For one object orbiting another under the influence of gravity, I = m*r^2 and omega = v/r, so

              ang mom  L  =     I     *  omega
  
                          = (m * r^2) * (v/r)
  
                          =   m * v * r
  

• The total angular momentum of a system is conserved, as long as no external forces act on it.

Copyright © Michael Richmond. This work is licensed under a Creative Commons License.