Angular Momentum
Another important tool in solving problems is Conservation of Momentum. Is there a similar tool for rotations?
We already have: p = mv and ?F = dp/dt.
If we multiply both sides of Newton’s Second law by the radius we have (with v = wr):
?t = r ??F = r ? dp/dt = d(r ? p)/dt = dL/dt
where we have defined L = r ? p, where L is called the Angular Momentum.