Two satellites $A$ and $B$,with a mass ratio of $3:1$,are in circular orbits of radii $r$ and $4r$ respectively. The ratio of the total mechanical energy of $A$ to $B$ is:

For a satellite orbiting around the earth in a circular orbit,the ratio of potential energy to kinetic energy at the same height is

$A$ 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:

$A$ launching vehicle carrying an artificial satellite of mass $m$ is set for launch on the surface of the earth of mass $M$ and radius $R$. If the satellite is intended to move in a circular orbit of radius $7R$,the minimum energy required to be spent by the launching vehicle on the satellite is ($G$ is the gravitational constant).

Initially, a satellite of $100 \ kg$ is in a circular orbit of radius $1.5 R_E$. This satellite can be moved to a circular orbit of radius $3 R_E$ by supplying $\alpha \times 10^6 \ J$ of energy. The value of $\alpha$ is . . . . . . .
(Take Radius of Earth $R_E = 6 \times 10^6 \ m$ and $g = 10 \ m/s^2$)

The additional kinetic energy to be provided to a satellite of mass $m$ revolving around a planet of mass $M$ to transfer it from a circular orbit of radius $R_1$ to another of radius $R_2$ $(R_2 > R_1)$ is: