Question

Two spheres of equal masses are placed at a distance of 100 m from their centers, if
the gravitational force of attraction between them is 1000N. Calculate the mass of each
sphere​

Answer 1

Answer:

The gravitational field at the mid-point of the line joining the centers of the two spheres =

(r/2)

2

GM

−

(r/2)

2

GM

=0 N

Gravitational potential at the midpoint of the line joining the centres of the two spheres is V=−

r/2

GM

−

r/2

GM

=−

r

4GM

V=−

0.1

4×6.67×10

−11

×100

=−2.68×10

−7

J/kg

As the effective force on the body placed at mid-point is zero, so the body is in equilibrium. If the body is displaced a little towards either mass body from its equilibrium position, it will not return back to its initial position of equilibrium. Hence, the body is in an unstable equilibrium.