Question

An artificial satellite is moving in a circular orbit of radius 42250 calculate it's speed if it takes 24hrs to revolves around the earth

Answer 1

distance=2πr
              =2×42250×22/7
              =265571.4 km

Time=24 hrs

Speed=distance/time
           =265571.4/24 
           =11065.4 km/hr

Answer 2

Radius, r = 42250 km

Time, t = 24 h

Speed = Circumference / time

=> 2πr / t

=> 2 ★ 3.14 ★ 42250 / 24

$\boxed{1105.54\:km/hr}$