Question

Let us consider the force of gravitation between two objects as F and distance between them as 'r'. What will be the effect on force if'r' is reduced to 1/4 th ??

Answer 1

Initially,

F = GMm/r^2 ----------------------(1)

Finally

F' = GMm/(r/4)^2 = 16GMm/r^2 ------------------(2)

Comparing (1) and (2)

F' = 16F

Hence, Force will become  16 times.