Here's why:
* Coulomb's Law: The force between two point charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them. Mathematically:
```
F = k * (q1 * q2) / r^2
```
where:
* F is the force
* k is Coulomb's constant
* q1 and q2 are the magnitudes of the charges
* r is the distance between the charges
* Doubling one charge: If you double one of the charges (let's say q1), the force will also double because the product (q1 * q2) in the formula is doubled.
In summary: If you increase one charge by a factor, the force between the charges will increase by the same factor.
