# How are electric forces and charge related?

May 16, 2014

The force between to point charges is calculated by Coulomb's Law:

• $F = \frac{k {Q}_{1} {Q}_{2}}{{r}^{2}}$ where ${Q}_{1}$ and ${Q}_{2}$ are the two charges in coulombs, k is the Coulomb constant ($8.9875 \times {10}^{9} \frac{N \cdot {m}^{2}}{{C}^{2}}$ ) , and r is the distance between the centers of the two charges in meters.

One charge creates an electric field throughout all of space, and it is the interaction with this field that causes the force on the second charge.