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

Explanation

Here `G=6.67xx10^(-11)Nm^(2)kg^(-2)M=100kg,R=0.1M`. Distance between the two spheres, d=1.0M
Suppose that the distance of either sphere from the mid point of the line joining their centre is r. then r=d/2=0.5m. The gravitational field at the mid-point due to two spheres will be eual and opposite.