Q.
If a satellite orbiting the Earth is 9 times closer to the Earth than the Moon, what is the time period of rotation of the satellite? Given rotational time period of Moon $=27$ days and gravitational attraction between the satellite and the moon is neglected.
A) 27 days
B) 1 day
C) 81 days
D) 3 days
Explanation
[Solution by Dr. Abubacker] Kepler's third law: $T^2\propto r^3$. $T=27\left(\frac19\right)^{3/2}=\frac{27}{27}=1$ day. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.