# WHAT IS COULOMB'S LAW

Source:  WHAT IS COULOMB'S LAW    Tag:  inverse square law definition
This law describe the electrostatic interaction between two charged bodies .. It is analogous to inverse-square law of universal gravitation . This is also known as inverse square law .

#### according to this law - the force between two charge particles is directly proportional to the multiplication of these two charges and inversely proportional to the square of distance separating these two charges .

Coulomb's law can also be stated as a simple mathematical expression. The scalar and vector forms of the mathematical equation are
$|\mathbf F|=k_e{|q_1q_2|\over r^2}\qquad$ and $\qquad\mathbf F_1=k_e\frac{q_1q_2}{{|\mathbf r_{21}|}^2} \mathbf{\hat{r}}_{21},\qquad$ respectively,
where  $k_e = 8.987\,551\,787\,368\,176\,4\times 10^9\ \mathrm{N\cdot m^2\cdot C}^{-2}$, is coulomb's constant $q_1$ and $q_2$ are the signed magnitudes of the charges, the scalar $r$ is the distance between the charges, the vector $\boldsymbol{r_{21}}=\boldsymbol{r_1-r_2}$ ,  and $\boldsymbol{\hat{r}_{21}}={\boldsymbol{r_{21}}/|\boldsymbol{r_{21}}|}$ (a unit vector pointing from $q_2$ to $q_1$).  It can be also calculated using newton's ;s: $\mathbf F_2=-\mathbf F_1$.