If the orbit of a rocket is a circle around the earth with a radius
= 8 x 106m, and the mass of the earth is 5.97 x 1024 kg while
that of the rocket is 0.5 x 106 kg, then what is the speed of the
rocket under uniform circular motion (in m/s, G = 6.67 * 10-11 N
(m/kg) ?)?