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.

We know that for any body total distance covered is equals to the circumference of that circular track. so, circumference of circular track = 2πr = 2 × π × 42250 = 265572 km
So, Distance = Speed × time
Speed = Distance / time = 265572 / 24 = 11065.4 km/hr = 3073.74 m/sec