A satellite is in a circular orbit around a planet. The radius of the orbit is 
and the period of the orbit is 
. The planet is a uniform sphere. Use Newton’s law of gravitation to show that and are related by:
where 
is the mass of the planet and 
is the gravitational constant.
The Earth may be considered to be a uniform sphere of mass 
and radius 
. A geostationary satellite is in orbit around the Earth. Use the expression in (a) to determine the height of the satellite above the Earth’s surface.
.
