Question

Relation between torque and angular momentum

Answer 1

angular momentum of a system remain constant if resultant external torque acting on it equal to zero.
As L=IxW so , if torque=0 then Iw=constant
where L is angular momentum
I is moment of inertia
W is angular velocity

Answer 2

Hey !!

We know that,

Torque,           τ = r × F

Angular momentum,     L = r × p

On differentiating both sides w.r.t time t, we get

         dL/dt = d/dt (r × p) = dr/dt × p × r × dp/dt

          = v × p + r × F                      [∴ dp/dt = F]

            = 0 + τ

∵              τ = dL/dt

Thus, the torque acting on a particle is equal to its rate of change of angular momentum.

Good luck !!