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Physical Sciences
Electromagnetism
1785
Beginner

Coulomb's Law

F=keq1q2r2F = k_e \frac{q_1 q_2}{r^2}

Electric force between charges is proportional to charge product and inversely proportional to distance squared.

By Charles-Augustin de Coulomb

Physical Sciences
Coulomb's Law
1785 · Charles-Augustin de Coulomb
Human Reviewed
84%

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Story PortalWho discovered this?Discover how Charles-Augustin de Coulomb and others shaped this equation.Visual PortalWhat does it look like?See the equation come alive in the Visual Studio.Machine PortalWhere is it used?Explore machines powered by this equation — capacitors.Math PortalWhat does it derive from?Trace the mathematical lineage from ohms law.Future PortalWhere is it going?Nanoelectronics
Why it matters: Foundation of electrostatics, chemistry, and electronics.

Discoverers: Charles-Augustin de Coulomb (1785)

What does it mean?

Electric force between charges is proportional to charge product and inversely proportional to distance squared.

Why should I care?

Foundation of electrostatics, chemistry, and electronics.

Equation Compass

North — Prerequisites

West — History

East — Applications

South — Derivations

Variables & Units

SymbolNameUnitMeaning
kek_eCoulomb constant—8.99×10⁹ N·m²/C²
q1,q2q₁,q₂ChargesCElectric charges
rrDistancemSeparation

Worked Example

Two 1 μC charges 1 m apart: F ≈ 9 N.

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Sources & further reading

Search WikipediaSearch Wolfram MathWorldOpen in Wolfram|AlphaWatch explainers on YouTube

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Equation Universe

Coulomb's Law

F=keq1q2r2F = k_e \frac{q_1 q_2}{r^2}

Real-world impact

Touchscreens & nanoelectronics

Inverse-square electrostatic force binds atoms in every chip and capacitive display.

Photo: Unsplash — smartphone touchscreen

Electric force between charges is proportional to charge product and inversely proportional to distance squared.

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