Question

A very small stone is tied to a string of length 1m. The string is clamped at A. A tangential force of 10 N is applied on the stone. What will be the rate of change of angular momentum of the stone with respect to point A?

• A. 20 N-m
• B. 15 N-m
• C. 30 N-m
• D. None of these

Answer 1

The correct option is D None of these

The net torque experienced by stone about $A=10\times 1N-m$
$=10N-m$

The rate of change of angular momentum is the applied net torque.
$\Rightarrow \frac{\left|d\overrightarrow{L}\right|}{dt}=10N-m$

Note: You can verify the same dimensionally.