Two point objects of mass $2x$ and $3x$ are separated by a distance $r$. Keeping the distance fixed,how much mass should be transferred from $3x$ to $2x$,so that the gravitational force between them becomes maximum?

Two spheres of mass $m$ and $M$ are situated in air and the gravitational force between them is $F$. The space around the masses is now filled with a liquid of specific gravity $3$. The gravitational force will now be

$A$ gravitational field is present in a region and a mass is shifted from $A$ to $B$ through different paths as shown. If $W_1, W_2$ and $W_3$ represent the work done by the gravitational force along the respective paths,then

$A$ rocket is fired from the Earth towards the Sun. At what distance from the Earth's centre is the gravitational force on the rocket zero? Mass of the Sun $= 2 \times 10^{30} \; kg$,mass of the Earth $= 6 \times 10^{24} \; kg$. Neglect the effect of other planets,etc. (Orbital radius $= 1.5 \times 10^{11} \; m$)

Gravitation is the phenomenon of interaction between ............

Three particles each of mass $m_{1}$ are placed at the corners of an equilateral triangle of side $\frac{L}{3}$. $A$ particle of mass $m_{2}$ is placed at the midpoint of any one side of the triangle. Due to the system of particles,the net gravitational force acting on $m_{2}$ is ($G$ = Universal constant of gravitation).