If the gravitational potential of an object of mass $m$ on the surface of the Earth is $\phi$,what is the gravitational potential of an object of mass $2m$?

Four particles each of mass $m$ are placed at the vertices of a square of side $l.$ The potential energy of the system is

Four particles $A, B, C$ and $D$ each of mass $m$ are kept at the corners of a square of side $L$. Now the particle $D$ is taken to infinity by an external agent,keeping the other particles fixed at their respective positions. The work done by the gravitational force acting on the particle $D$ during its movement is ..........

The gravitational field in a region is given by the equation $E = (5\hat{i} + 12\hat{j}) \text{ N/kg}$. If a particle of mass $2 \text{ kg}$ is moved from the origin $(0, 0)$ to the point $(12 \text{ m}, 5 \text{ m})$ in this region, the change in gravitational potential energy is: (in $\text{ J}$)

If $g$ is the acceleration due to gravity on the earth's surface,the gain in the potential energy of an object of mass $m$ raised from the surface of the earth to a height equal to the radius $R$ of the earth is

Two bodies of masses $4 \,m$ and $9 \,m$ are separated by a distance $r$. The gravitational potential at a point on the line joining them where the gravitational field becomes zero is: