Coulomb’s Law Calculator

First charge q1 (C):
Second charge q2 (C):
Distance between charges r (m):
Calculate

 

Introduction

Electricity and magnetism are fundamental forces that govern the behavior of matter in our universe. Coulomb’s Law is a fundamental principle in electrostatics, helping us understand how electric charges interact with each other. Whether you’re a student studying physics or someone with a keen interest in understanding the world around you, knowing how to calculate electric force using Coulomb’s Law is invaluable.

In this article, we will break down the essential components of Coulomb’s Law, provide you with a user-friendly formula, walk you through an example calculation, address common questions in our FAQs section, and even offer you a convenient HTML calculator that simplifies the math. So, let’s dive in and explore the world of electric forces.

Formula

Coulomb’s Law describes the electric force ($F$) between two point charges (q1​ and q2​) separated by a distance ($r$). The formula for Coulomb’s Law is as follows:

F=r2k⋅∣q1​⋅q2​∣/r2​

Where:

• $F$ is the electric force between the charges (measured in newton, N).
• q1​ and q2​ are the magnitudes of the charges (measured in coulombs, C).
• $r$ is the distance between the charges (measured in meters, m).
• $k$ is the electrostatic constant, also known as Coulomb’s constant, with a value of approximately 8.99×109 N m2/C28.99×109N m2/C2.

Now that we have the formula, let’s see how it works with a practical example.

Example

Problem: Calculate the electric force between two point charges. Charge q1​ is $5\text{C}$, charge q2​ is $3\text{C}$, and they are separated by a distance of $2\text{m}$.

Solution:

Plug the given values into Coulomb’s Law formula:

F=r2k⋅∣q1​⋅q2​∣/r2​

F=(8.99×109 N m2/C2)⋅(5 C)⋅(3 C)(2 m)2F=(2m)2(8.99×109N m2/C2)⋅(5C)⋅(3C)​

F=13485000000 N m2/C24 m2F=4m213485000000N m2/C2​

$F=3371250000\text{N}$

So, the electric force between these two charges is $3,371,250,000\text{N}$.

Now that you’ve seen how to calculate electric force using Coulomb’s Law, you might have some questions. Let’s address those in our FAQs section.

FAQs

Q1: What are the units of the electrostatic constant ($k$) in Coulomb’s Law?

A1: The units of $k$ are N m2/C2N m2/C2.

Q2: Is Coulomb’s Law applicable to point charges only?

A2: Yes, Coulomb’s Law is specifically applicable to point charges. It simplifies the calculation of electric force between charged particles when they are treated as point charges.

Q3: Can Coulomb’s Law be used for charges with opposite signs?

A3: Yes, Coulomb’s Law can be used for charges with opposite signs. The force will be attractive if the charges have opposite signs and repulsive if they have the same sign.

Conclusion

Coulomb’s Law is a fundamental concept in physics that allows us to understand and calculate the electric force between charged particles. With the formula, example, and FAQs provided in this article, you should now have a solid understanding of how to apply Coulomb’s Law to solve problems related to electric forces.