Satellite revolving very near to the earth’s surface:
If a satellite remains very near to the earth’s surface, i.e., if h is very small compared to R, i.e., those satellites that revolve round the earth in larger orbit, then their time periods become large and velocity of rotation becomes small. Clearly, there is a fixed magnitude of velocity in each orbit. If a satellite is placed at a velocity smaller than this critical velocity, then that satellite cannot revolve round the earth permanently and it will come down on the earth.
Satellites are natural or artificial bodies revolving around a planet under its gravitational attraction. Moon is a natural satellite where as INSAT-1B is an artificial satellite. The orbital speed of satellite revolving near the surface of the earth is 7.9 km/sec. Period of revolution of a satellite depends upon the height of satellite from the surface of the earth. Greater the heights more will be the stage of revolution. The period of revolution of satellite near the surface of the earth is 1 hour 24 minute (84 minute).