State Coulomb's law.

Explanation

### Step-by-Step Solution:

1. **Understanding the Concept**: Coulomb's law describes the interaction between two charged bodies. It explains how the force between them depends on their charges and the distance separating them.

2. **Statement of Coulomb's Law**:
- The law states that the magnitude of the electrostatic force \( F \) between two point charges \( q_1 \) and \( q_2 \) is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance \( r \) between them.

3. **Mathematical Representation**:
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