Question

What will happen to the gravitational force between two bodies if they are brougth closer by half of their initial separation?

Answer 1

actually
F=GMm/r^2 -------(1)
it means gravitational force is inversely proportional to square of separation between two objects
now question ask
objects are come closer half of initial position .
now
F'=GMm/(r/2)^2=4.GMm/r^2
from equation (1)
F'=4F
hence increase 4 times from initial force.

Answer 2

According to** Newton's** laws of gravitation. ....

F <proportional> 1/r^2
so...
IF DISTANCE BETWEEN BODIES REDUCED TO HALF THEN FORCE BETWEEN THEN BECOMES ""4 times the original value""