Question

Adding to Newton’s law of universal gravitation, the gravitational force between two masses is proportional to 1/r^2, where r is the distance between the masses. Surprisingly, the electric force between two electric charges is also proportional to 1/r^2, where r is the distance between the electric charges. (Coulomb’s law) These facts are called the “inverse-square laws” -> Now give “your answer” to the question: Why (or How) are these forces proportional to 1/r^2 (not 1/r, 1/r^3, 1/r^100, etc)?

Answer 1

The electrostatic force is the force between the two charges and gravitational force is between two masses.

The logic of the inverse square law comes from the experimental data.

When the Newton study about these forces then he collect the experimental data and arrange according to the order. Then he see that the force depends upon the distance between the two particles. For the exact dependency of the distance he makes curves for these forces ans see that the variation is depends upon inverse of square.

And the formula is valid at each and every case at all conditions. So, he conclude and come to the result that the Gravitational and Electrostatic force depends upon inverse of square.

The experimental data need no Proof.

Thanks.