$A$ skylab of mass $m \ kg$ is first launched from the surface of the earth into a circular orbit of radius $2R$ (from the centre of the earth) and then it is shifted from this circular orbit to another circular orbit of radius $3R$. The minimum energy required to shift the lab from the first orbit to the second orbit is:

Choose the correct alternative:
$(a)$ If the zero of potential energy is at infinity,the total energy of an orbiting satellite is negative of its kinetic/potential energy.
$(b)$ The energy required to launch an orbiting satellite out of Earth's gravitational influence is more/less than the energy required to project a stationary object at the same height (as the satellite) out of Earth's influence.

In an orbit,if the time of revolution of a satellite is $T$,then the potential energy $(PE)$ is proportional to:

Two satellites $A$ and $B$,having a ratio of masses $3 : 1$,are in circular orbits of radius $r$ and $4r$ respectively. Calculate the ratio of the total mechanical energy of $A$ and $B$.

$A$ satellite of earth of mass $m$ is moved from an orbital radius of $2R$ to $3R$. Calculate the minimum work done.

In a satellite,if the time of revolution is $T$,then $KE$ is proportional to