Question

Write the relation between angular momentum and torque$.$ What is the torque acting on a body rotating with constant angular momentum$?$

Answer 1

Relation between torque and angular momentum is given by

${\overrightarrow{r}}_{net}=\frac{d\overrightarrow{L}}{dt}$

where, $\overrightarrow{r}\to$ torque acting on a body

$\overrightarrow{L}\to$ angular momentum of body

Now if, $\overrightarrow{L}=$ constant

So, $\frac{d\overrightarrow{L}}{dt}=0$

$\Rightarrow {\overrightarrow{r}}_{net}=0$

Hence,

If a body is rotating with constant angular momentum then, the net torque on the body will be zero.