Q. If the earth is treated as a sphere of radius $R$ and mass $M$; its angular momentum about axis of rotation with period $T$ is
A) $\frac{\pi{MR}^{3}}{T}$
B) $\frac{{MR}^{2}\pi}{T}$
C) $\frac{2\pi{MR}^{3}}{5T}$
D) $\frac{4\pi{MR}^{2}}{5T}$
Explanation
(d) Angular momentum is given by
$J = I\omega = \left( \frac{2MR^{2}}{5} \right)\omega$
$= \frac{2MR^{2}}{5} \times \frac{2\pi}{T} = \frac{4\pi MR^{2}}{5T}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.