Why gravitational force of attraction is necessary for a satellite to revolve around earth?

The question was posted by Raj Kumar. The satellite has a velocity. To revolve around, the direction of velocity must change. In the absence of a force it can move only in a straight line. It is the gravitational force which helps the satellite top change direction and revolve around the earth. In other words, for a [...]

Misconception on Work and energy conservation

It is said that when work is done energy is lost. But when a man runs in a circular path and reaches the starting point, then the work done is zero but energy is lost. (Divyam asked) Answer: The work done here is not zero, work is done and energy is spent to overcome friction. [...]