1. What is Coulomb's Law?

Definition: Coulomb's Law describes the electrostatic force between two charged particles. The force is proportional to the product of the charges and inversely proportional to the square of the distance between them.

Purpose: This fundamental law of physics helps calculate the attractive or repulsive force between charged objects.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( F \) — Electric force (Newtons)
• \( k \) — Coulomb's constant (8.99×10⁹ N·m²/C²)
• \( q_1 \) — First charge (Coulombs)
• \( q_2 \) — Second charge (Coulombs)
• \( r \) — Distance between charges (meters)

Explanation: The force is directly proportional to the product of the charges and inversely proportional to the square of their separation.

3. Importance of Coulomb's Law

Details: Understanding electric forces is crucial in fields ranging from atomic physics to electrical engineering. It explains phenomena from atomic bonding to static electricity.

4. Using the Calculator

Tips: Enter both charges in Coulombs (1 electron = 1.6×10⁻¹⁹ C) and the distance in meters. The distance must be greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What does a negative force value mean?
A: Negative values indicate attractive forces (between opposite charges), while positive values indicate repulsion (between like charges).

Q2: Why is the constant k so large?
A: The large value compensates for the typically very small charge values measured in Coulombs.

Q3: Does this work for point charges only?
A: The formula is exact for point charges and approximately valid for spherical charges if r is much larger than their diameters.

Q4: How does medium affect the force?
A: In other media, divide the result by the relative permittivity (εᵣ) of the medium.

Q5: What's the relationship with gravity?
A: Both follow inverse-square laws, but electric forces are typically much stronger than gravitational forces.