Coulomb force

Definition

Coulomb force, also known as the electrostatic force, is the force of attraction or repulsion between two charged particles. It follows an inverse-square law and is governed by Coulomb's law.

5 Must Know Facts For Your Next Test

1. The magnitude of the Coulomb force between two charges is given by $F = k \frac{|q_1 q_2|}{r^2}$ where $k$ is Coulomb's constant.
2. Coulomb's constant $k$ has a value of approximately $8.99 \times 10^9 \, N \, m^2 / C^2$ in a vacuum.
3. The direction of the Coulomb force depends on the signs of the charges: like charges repel and opposite charges attract.
4. Coulomb force acts along the line joining the centers of two charged particles.
5. The principle of superposition applies to Coulomb forces, meaning that the net force on a charge due to multiple other charges is the vector sum of all individual forces.

Review Questions

• What is the formula for calculating Coulomb force?
• How does the direction of Coulomb force relate to the types of charges involved?
• What does it mean that Coulomb force follows an inverse-square law?

Related terms

Electric Field: A region around a charged particle where a force would be exerted on other charged particles.

Electrostatics: The study of stationary electric charges or fields as opposed to electric currents.

Inverse-square Law: A physical principle stating that a specified physical quantity or intensity is inversely proportional to the square of the distance from the source.