Question

If Q₂ and Q₃ are separated by a distance of 20 cm and have the same charge of 50μC, what is the magnitude of the force between them?

Answer 1

The Coulomb's law says

$$F=k\frac{q_1q_2}{r^2}$$

$$F=9\times 10^9\times \frac{50\times 10^{-6}\times 50\times 10^{-6}}{0.20^2}=562.5\:\rm N$$