Coulomb’s Law Force Calculator
Compute electrostatic force, charge magnitude, or separation distance using Coulomb's Law. Includes dielectric medium adjustments and vector direction indicators.
About
Electrostatic force calculations are fundamental to engineering fields ranging from capacitor design to particle physics. This tool solves for any variable in the Coulomb interaction equation - Force, Charge, or Distance - while accounting for the permittivity of the intervening medium. Unlike basic vacuum-only calculators, this interface permits the inclusion of a relative dielectric constant, essential for applications involving insulators or fluid mediums like water.
Precision is maintained through scientific notation handling, allowing accurate computation of interactions between subatomic particles or macroscopic static charges. The visual output distinguishes between attractive and repulsive vectors, immediate validation for vector analysis tasks.
Formulas
The scalar magnitude of the electrostatic force is defined by:
F = ke ⋅ |q1 ⋅ q2|εr ⋅ r2
Where ke is Coulomb's constant (≈ 8.987 × 109 N⋅m2/C2), εr is the relative permittivity (dielectric constant) of the medium, q represents the point charges, and r is the separation distance.
Reference Data
| Medium | Dielectric Constant (εr) | Effect on Force |
|---|---|---|
| Vacuum | 1.0000 | Baseline Force (100%) |
| Air (STP) | 1.0006 | Negligible reduction |
| Paper | 3.7 | ≈ 27% of Vacuum Force |
| Glass (Pyrex) | 5.6 | ≈ 18% of Vacuum Force |
| Rubber | 7.0 | ≈ 14% of Vacuum Force |
| Water (20°C) | 80.1 | ≈ 1.2% of Vacuum Force |
| Ceramic (Titanate) | 1000+ | Extreme shielding |