Coulomb's Law
F = k·q₁·q₂ / r²
What it means
Coulomb's law gives the electrostatic force between two point charges — the electric analogue of Newton's law of gravitation.
Variables
| Symbol | Quantity | SI unit |
|---|---|---|
F | force | N |
k | Coulomb constant | N·m²/C² |
q₁ | charge | C |
q₂ | charge | C |
r | distance | m |
Worked example
Given q₁ = 1.0000e-6 C, q₂ = 1.0000e-6 C, r = 0.1 m, k = 8.9880e+9 N·m²/C², solve for F:
F = 0.8988 N