According to the Newton's gravitational law, two bodies exert an attractive gravitational force on each other. This force is equal to the product of their masses and inversely proportional to the square of the distance between them. This force depends on two factors that are product of masses and distance between the bodies. The formula for gravitational force is;

F= Gm

G= gravitational constant

m

m

r= distance between two bodies

The value of gravitational constant is 6.673 × 10

F= Gm

_{1}m_{2}/ r^{2}G= gravitational constant

m

_{1}= mass of first bodym

_{2}= mass of second bodyr= distance between two bodies

The value of gravitational constant is 6.673 × 10

^{−11}N m^{2}kg^{-2}.