Question

A train of mass $M$ is moving on a circular track of radius '$R$' with constant speed $V$. The length of the train is half of the perimeter of the track. The angular momentum of the train about the centre of circular track will be :

• A. $zero$
• B. $\frac{2MV}{\pi }$
• C. $MVR$
• D. $MV$

Answer 1

Answer: (C)

$MVR$

The angular momentum is given as $L=I\omega$. The moment of inertia of the train of given mass M about the center of the circular track is $M{R}^2$ and the angular velocity is $\omega =\frac{V}{R}$
Thus we get the angular momentum as $L=\left(M{R}^2\right)\frac{V}{R}=MVR$