Question

When is Angular Momentum Conserved???

Answer 1

When the resultant external torque acting on the system is zero , the total vector angular momentum of the system remains constant.

Answer 2

We know that \[L=I \omega\]
That is Angular momentum is equal to product of moment of inertia and angular velocity.
Now differentiating with respect to time,
\[dL/dt=d(I \omega)/dt\]
Bu we know that the rate of change of angular momentum is equal to net external torque i.e.
\[dL/dt=\tau\]

therefore
if no exterannal torque is acting on the body i.e. \[\tau=0\]then
\[dL/dt=0\]

in other words
\[d(I \omega)/dt=0\] because \[dL/dt=d(I \omega)/dt\]

Hence angular momentum is conserved or angular momentun does not change with time if the net external force acting on the body is zero.

Answer 3

agree with santosh k

Answer 4

when there is no external torque to the system the angular momentum would be conserved.