Physics Class 11 Chapter 8. Gravitation | Page 11

PSLV series satellites are polar satellites of India .
Orbital Velocity
Orbital velocity of a satellite is the minimum velocity required to the satellite into a given orbit around earth .
Orbital velocity of a satellite is given by vo = √GM / r = R √g / R + h
where , M = mass of the planet , R = radius of the planet and h = height of the satellite from planet ’ s surface .
If satellite is revolving near the earth ’ s surface , then r = ( R + h ) = - R Now orbital velocity ,
vo = √gR = 7.92km / h
if v is the speed of a satellite in its orbit and vo is the required orbital velocity to move in the orbit , then
( i ) If v < vo , then satellite will move on a parabolic path and satellite falls back to earth .
( ii ) If V = vo then satellite revolves in circular path / orbit around earth . ( iii ) If vo < V < ve then satellite shall revolve around earth in elliptical orbit .
Energy of a Satellite in Orbit Total energy of a satellite E = KE + PE
= GMm / 2r + ( - GMm / r ) = – GMm / 2r