Coulomb's Law
An inverse-square law stating that the electrostatic force between two stationary point charges is directly proportional to the product of their charges and inversely proportional to the square of their separation distance.
Governing formula
F = k_e |q₁ q₂| / r² = (1 / (4π ε₀)) |q₁ q₂| / r²
SI unit
N (Newtons)
In depth
The Coulomb constant k_e ≈ 8.9875 × 10⁹ N·m²/C². The force acts along the straight line connecting the charges, acting as an attractive force between opposite charges and a repulsive force between like charges.
Examples in the real world
The electrostatic force binding negatively charged orbital electrons to the positively charged atomic nucleus.