Q. A satellite is to revolve round the earth in a circle of radius $8000\ km$. The speed at which this satellite be projected into an orbit, will be
A) $3\ km/s$
B) $16\ km/s$
C) $7.15\ km/s$
D) $8\ km/s$
Explanation
(c) $v_{0} = \sqrt{\frac{GM}{r}} = \sqrt{\frac{gR^{2}}{r}} = \sqrt{\frac{10 \times \left( 64 \times 10^{5} \right)^{2}}{8000 \times 10^{3}}}$
$= 71.5 \times 10^{2}m/s = 7.15\ km/s$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.