Coulomb Force Calculator

How to use it

1. Q₁ = 2.5×10⁻⁶ C, qâ‚‚ = -1.8×10⁻⁶ C, r = 0.15 m
2. Square distance: 0.15² = 0.0225
3. Multiply: k × q₁ × qâ‚‚ = 8.9875×10⁹ × 2.5×10⁻⁶ × (-1.8×10⁻⁶)
4. Divide by r²: F ≈ -1.7975 N (attractive)

Common mistakes

• ⚠️ Forgetting to square the distance
• ⚠️ Not handling sign of charg is (attraction vs repulsion)
• ⚠️ Using wrong value for Coulomb constant k

Worked example

Calculate Coulomb force between charg is of 2.5 μC and -1.8 μC separated by 0.15 m.

The Coulomb force {force} N between the charg is (negative means attraction).

Input guide