# Coulomb's Law Definition

In physics, coulomb's law is defined as the **force of repulsion or attraction** **among the points of two charges** that are **directly proportional** to the **multiplicative product of the charge's magnitudes** and **inversely proportional** to the **distance of square between the charges**. For instance, in ancient times, the tribes living around the Mediterranean Sea used a technique that defines coulomb's law. To attract or catch lighter objects like feathers, they rubbed a rod of amber on a cat's fur so that the force of attraction is caused by the points of two charges.

**Table of Contents**

## Formula of Coulomb's Law

The formula used for coulomb's law is listed below:

\[F = K(\frac{{{q_1}\;.\;{q_2}}}{{{{\rm{r}}^2}}})\]

**Where,**

F = Electrostatic attraction or repulsion force

q_{1} = Intensity of 1st point charge

q_{2} = Intensity of 2nd point charge

r = Distance among them

K = Coulomb’s constant

**Note:**

To calculate Coulomb's law, you can use our Coulomb's Law Calculator.

### Example

For a better understanding, we have a solved example of Coulomb’s law as follows:

What is the intensity of the force between two charges having a magnitude of 5 C which are 10 meters apart?

**Given data**

r = 10m

q_{1}= 5C

q_{2}= 5C

**To Find**

Intensity of the force = ?

**Solution**

To find the intensity of the force, we can use the formula listed below:

\[F = K(\frac{{{q_1}\;.\;{q_2}}}{{{{\rm{r}}^2}}})\]

Putting values in the formula:

F = 9.0 x 10^{9}* 5 * 5 / (10 * 10)

F = 2.25 * 10^{9}N