LaTeX
F=k\frac{|q_1q_2|}{r^2}Variables
- F: force magnitude
- k: Coulomb constant
- q₁, q₂: electric charges
- r: separation distance
How to use this formula
Calculates the magnitude of the electrostatic force between two point charges.
Important notes
- The force direction depends on the signs of the charges.
- The point-charge approximation must be appropriate.
Quick example
Doubling the separation reduces the force to one quarter.
Applicability, worked calculation, and verification
Assumptions and domain checks
- The force direction depends on the signs of the charges.
- For the Coulomb's Law, every denominator must be nonzero, and the numerator and denominator must remain correctly grouped.
- Use dimensionally consistent units and the sign, coordinate, and reference-frame conventions stated for the problem.
Worked example
Doubling the separation reduces the force to one quarter.
Common mistakes
- When copying Coulomb's Law, keep the complete numerator and denominator grouped; a missing brace or parenthesis changes the result.
- Verify the result of Coulomb's Law with a known case, inverse operation, dimensional check, or independent calculation before publishing it.
Continue the workflow
Use Coulomb's Law in your own work
- Check the domainMatch the variables and assumptions to the problem before substituting values.
- Copy the exact notationPreserve grouping, signs, and exponents in
F=k\frac{|q_1q_2|}{r^2}. - Edit or convertOpen the expression in the LaTeX editor, then export it for your document or web page.
Review and verification
Last reviewed: 2026-07-23
Automated quality check: Kept noindex until the missing evidence is supplied.
Formula references
- College Physics 2eOpenStax, Rice University — Reviewed physical quantities, units, mechanics, energy, waves, electricity, and applied formulas.
Frequently asked questions
What is the Coulomb's Law used for?
Calculates the magnitude of the electrostatic force between two point charges.
Can I copy this formula as LaTeX?
Yes. Copy F=k\frac{|q_1q_2|}{r^2} or open it in the LaTeX editor.
What should I check before using it?
Confirm that each variable, unit, domain restriction, and assumption matches the problem.