Q. A satellite is placed in a circular orbit around earth at such a height that it always remains stationary with respect to earth surface. In such case, its height from the earth surface is
A) 32000 km
B) 36000 km
C) 6400 km
D) 4800 km
Explanation
(b) $h = \left( \frac{T^{2}R^{2}}{4\pi^{2}} \right)^{1/3} - R$
$= \left\lbrack \frac{(24 \times 60 \times 60)^{2} \times \left( 6.4 \times 10^{6} \right)^{2} \times 9.8}{4 \times (22/7)^{2}} \right\rbrack^{1/3} - 6.4 \times 10^{6}$
$= 3.6 \times 10^{7}$m = 36000 km
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.