Taking the gravitational potential at a point at an infinite distance away as zero,the gravitational potential at a point $A$ is $-5 \, unit$. If the gravitational potential at a point at an infinite distance away is taken as $+10 \, units$,the potential at point $A$ is ......... $unit$.

Why does the potential energy of an object increase when it is raised above the surface of the Earth?

$A$ body of mass $m$ is taken from the surface of earth to a height equal to twice the radius of earth $(R_e)$. The increase in potential energy will be . . . . . . . ($g$ is acceleration due to gravity at the surface of earth)

The particles $A$ and $B$ of mass $m$ each are separated by a distance $r$. Another particle $C$ of mass $M$ is placed at the midpoint of $A$ and $B$. Find the work done in moving $C$ to a point equidistant $r$ from $A$ and $B$ without acceleration. ($G$ is the gravitational constant and only gravitational interaction between $A, B$ and $C$ is considered.)

Three masses $m, 2m$ and $3m$ are arranged in two triangular configurations as shown in figure $1$ and figure $2$. The work done by an external agent in changing the configuration from figure $1$ to figure $2$ is:

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