Question

A body of mass $10kg$ and radius of gyration $0.1m$ is rotating about an axis. If angular speed is $10rad/s$, then angular momentum will be?

• A. $1kg{m}^2/s$
• B. $0.1kg{m}^2/s$
• C. $100kg{m}^2/s$
• D. $10kg{m}^2/s$

Answer 1

Answer: (A)

$1kg{m}^2/s$

We know angular momentum=I$\omega$---(1) where I= moment of inertia and $\omega$= angular speed

Also moment of inertia I=$k^{2}m={0.1}^2\times 10=0.1kg{m}^2$ where k= radius of gyration(0.1 m) and m= mass(10 kg)

Putting the values in equation 1 we get

Angular momentum=0.1$\times$10=1 kg $m^2$/s