Q. When a satellite going round the earth in a circular orbit of radius $r$ and speed $v$ loses some of its energy, then $r$ and $v$ change as
A) $r$ and $v$ both will increase
B) $r$ and $v$ both will decrease
C) $r$ will decrease and $v$ will increase
D) $r$ will decrease and $v$ will decrease
Explanation
(c) $B.E. = - \frac{GMm}{r}$. If $B.E.$ decreases then $r$ also decreases and $v$ increases as $v \propto \frac{1}{\sqrt{r}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.