Coulomb's Law¶

The electrostatics force $\vec{F}$ between two point charges $q_1$ and $q_2$ is

$$\large \vec{F} = k_e \frac{q_1 q_2}{r^2}\hat{r}$$

where

$k_e$: Coulomb's constant $(= \frac{1}{4\pi \epsilon_0})$

$q_{1,2}$: point charges

$r$: distance between the charges.

Vector Sum¶

Since the electrostatic force is a vector, the net force is the result of adding all the forces together as vectors.

• GRE Physics GR1777 Problem 039