Oct. 31, 2019

Law of Conservation of Angular Momentum:

Law of Conservation of Angular Momentum :

(1) If the net external torque on a particle (or system) is zero then

i.e.= constant

Angular momentum of a system (may be particle or body) remains constant
if resultant torque acting on it is equal to zero.

As L = Iω,  so if , then Iω = constant  ∴ 

Since angular momentumIω remains constant so when I decreases, angular velocity ω increases and vice-versa.