At some point,the gravitational potential and the gravitational field due to the Earth are both zero. This point is:

Two heavy spheres each of mass $100 \; kg$ and radius $0.10 \; m$ are placed $1.0 \; m$ apart on a horizontal table. What is the gravitational force and potential at the mid-point of the line joining the centres of the spheres? Is an object placed at that point in equilibrium? If so,is the equilibrium stable or unstable?

When an object is brought from infinity to a distance $r$ from a mass,its gravitational potential energy ....... . (Fill in the blank)

$A$ star is modeled as a uniform spherical distribution of matter,keeping the mass of the star constant. How does the gravitational pressure on the surface depend on the volume of the star?

$A$ body of mass $m$ rises to a height $h = R/5$ from the earth's surface,where $R$ is the earth's radius. If $g$ is the acceleration due to gravity at the earth's surface,the increase in potential energy is:

$A$ body of mass $m$ is kept at a small height $h$ above the ground. If the radius of the earth is $R$ and its mass is $M$,the potential energy of the body and earth system (with $h = \infty$ being the reference position) is