Question

Two point charges separated by a distance d repel each other with a force of 9N. If the separation between them becomes 3d, the force of repulsion will be?

Answer 1

Answer:

1 N

Explanation:

According to Coulomb's law, the charge force between 2 charges is inversely proportional to their distance squared. So if you increase the separation between them by 3 folds, their charge force would drop by a factor of $3^2 = 9$. So the new force would be 9 / 9 = 1N