Derive an expression for the periodic-time of a satellite revolving around the earth. Show how it depends upon the density of the earth.

 A satellite of mass $m$ is revolving around the earth in a circular orbit of radius $\mathrm{r}.$ Write the expressions for the kinetic energy and the total energy of this satellite. Why is the total energy negative?

 A satellite of mass $m$ is revolving around the earth in a circular orbit of radius $\mathrm{r}.$ What will be escape velocity for this satellite?

A satellite of mass $m$ is revolving around the earth in a circular orbit of radius $r$. Show that this satellite obeys Kepler's third law, according to which, the ratio of the cube of its orbit's radius to the square of its period of revolution is constant.