Coulomb's law states that the force between two charged objects, regarded as point charges q1 and q2, is directly proportional to the product of the quantity of charge on the objects and inversely proportional to the square of the separation distance r between the two objects. It is now usually stated in the form:
F = q1 q2 / 4πεr 2
where ε is the absolute permittivity of the intervening medium.
The law is named after its discoverer, Charles Coulomb.
See also Coulomb's law for magnets.