Coulomb's Law Calculator Formula

Understand the math behind the coulomb's law calculator. Each variable explained with a worked example.

Use the Coulomb's Law Calculator

Formulas Used

Electrostatic Force

force = 8.9875e9 * abs(q1 * q2) / pow(distance, 2)

Variables

VariableDescriptionDefault
q1Charge 1(C)0.000001
q2Charge 2(C)0.000002
distanceDistance(m)0.05

How It Works

Coulomb's Law

Coulomb's law gives the magnitude of the electrostatic force between two point charges.

Formula

F = k * |q1 * q2| / r²

where k = 8.9875 x 10^9 N·m²/C². Like charges repel, unlike charges attract.

Worked Example

Two charges (1 μC and 2 μC) separated by 5 cm.

q1 = 0.000001q2 = 0.000002distance = 0.05
  1. 01F = k * |q1 * q2| / r²
  2. 02F = 8.9875e9 * |1e-6 * 2e-6| / 0.05²
  3. 03F = 8.9875e9 * 2e-12 / 0.0025
  4. 04F = 0.01798 / 0.0025 = 7.19 N

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