Near the earth surface , time period of the satellite T = 2π √R 3 / GM = √3π / Gp
T = 2π √R / g = 5.08 * 10 3 s = 84 min .
where p is the average density of earth . Artificial satellites are of two types :
1 . Geostationary or Parking Satellites
A satellite which appears to be at a fixed position at a definite height to an observer on earth is called geostationary or parking satellite .
Height from earth ’ s surface = 36000 km
Radius of orbit = 42400 km
Time period = 24 h
Orbital velocity = 3.1 km / s
Angular velocity = 2π / 24 = π / 12 rad / h
There satellites revolve around the earth in equatorial orbits .