Coulomb's law states that the electrostatic force F 1 experienced by a charge, q 1 at position r 1 , in the vicinity of another charge, q 2 at position r 2 , in a vacuum is equal to F 1 = q 1 q 2 4 π π ε ε 0 r ^ ^ 12 | r 12 | 2 = q 1 q 2 4 π π ε ε 0 r 12 | r 12 | 3