$A$ particle of mass $M$ is placed at the centre of a uniform spherical shell of mass $2M$ and radius $R$. The gravitational potential on the surface of the shell is

$A$ stationary body on the surface of the Earth has negative potential energy. What does this indicate?

Two point masses having mass $M$ and $4 M$ are placed at a distance $r$. The gravitational potential at a point,where the gravitational field intensity is zero,is ..............

An object is taken to a height of $2R$ above the surface of the Earth. What is the increase in its gravitational potential energy? [$R$ is the radius of the Earth]

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?

If one wants to remove all the mass of the earth to infinity in order to break it up completely,the amount of energy that needs to be supplied will be $\frac{x}{5} \frac{GM^2}{R}$,where $x$ is .......... (Round off to the Nearest Integer). ($M$ is the mass of earth,$R$ is the radius of earth,$G$ is the gravitational constant)