Question

how does the magnitude of gravitational force on the two bodies depends on the distance of separation between them

Answer 1

Since gravitational force is inversely proportional to the square of the separation distance between the two interacting objects, more separation distance will result in weaker gravitational forces. So as two objects are separated from each other, the force of gravitational attraction between them also decreases.

Answer 2

The gravitational force between two objects of mass M and m separated by a distance R is given by:

$\text{gravitational force} = \frac{GMm}{ {R}^{2} }$

We can see that the magnitude of gravitational force on the two bodies is inversely proportional to the distance of separation between them.

$\textbf{force \:} \alpha \: \: \frac{ \bold1}{ \bold{{R}^{2} }}$

This means the gravitational force between two objects will decrease rapidly if we increase the distance between them.

We can also say, that the gravitational force between two point masses will be highest when they are in contact as R will be minimum when they are in contact.