Objects of mass $m$ are placed on the $x$-axis at $x = 1, x = 2, x = 4, x = 8, \dots$ respectively. What is the gravitational potential at the origin $x = 0$?

The gravitational potential energy of a system of three masses $m$,$2m$,and $3m$ placed at the three vertices of an equilateral triangle of side '$a$' is:

The curves for potential energy $(U)$ and kinetic energy $(E_k)$ of a two-particle system are shown in the figure. At what points will the system be bound?

Four spheres each of mass $m$ form a square of side $d$ (as shown in the figure). $A$ fifth sphere of mass $M$ is situated at the centre of the square. The total gravitational potential energy of the system is

Two bodies of masses $m$ and $4m$ are placed at a distance $r$. The gravitational potential at a point on the line joining them where the gravitational field is zero is

An infinite number of objects,each of mass $1 \ kg$,are placed on the $x$-axis on both sides of $x=0$ at positions $x = \pm 1 \ m, \pm 2 \ m, \pm 4 \ m, \pm 8 \ m, \ldots$ and so on. The magnitude of the resultant gravitational potential (in $SI$ units) at $x=0$ is ($G$ is the universal gravitational constant).