What is the equation for calculating the electrical force, fe, between two charges?

When 2 electric charges are place close to each other they experience a force between them. This force may be repulsive or attractive depending on the type of charges involved.

The magnitude of this force depend on the quantity of individual charges and the distance between them.

The force is defined  by the Coulomb's law states that: The magnitude of the electrostatic force of attraction or repulsion between two point charges is directly proportional to the product of the magnitudes of charges and inversely proportional to the square of the distance between them.

The formula for calculating the force between 2 electric charges is ;

F = (kq₁q₂)/d²

Where  k is the proportionality constant known as Coulomb's constant,

            q₁ and q₂ are the charges and

            d is the distance between q₁ and q₂.