Question

An artificial satellite is moving in a circular orbit of radius 42250 km. Calculate its speed if it takes 24 hours to revolve around the Earth.

• A. 2.07 km/s
• B. 3.07 km/s
• C. 4.21 km/s
• D. 1.28 km/s

Answer 1

The correct option is B

3.07 km/s

The distance covered by the satellite in 24 hours is the circumference of the circular orbit.
Speed $=\frac{Circumferenceoforbit}{Timeperiod}$

$=\frac{2\pi R}{T}$

$=\frac{2\times \pi \times 42250}{24\times 3600}$ $\frac{km}{s}$
$[\because 1hr=60\times 60=3600s]$

$=3.07\frac{km}{s}$