Question

An artificial satellite orbiting the earth in very thin atmosphere loses its energy gradually due to dissipation against atmospheric resistance, however small. Why then does its speed increase progressively as it comes closer and closer to the earth?

Answer 1

This can be explained through Newton's Universe Law of Gravitation.

As the orbitting comes closer and closer to the Earth, The Gravitational force increases on the revolving body. This causes a subsequent increase in the acceleration of the body. Hence, even the speed of revolution increases.

The formula for orbital velocity is

V=(GM/R)^0.5.

The formula also depicts that as the distance between the planet and the revolving object decreases the speed correspondingly increases.