Question

If two like charges, each having a charge of four micro coulombs sit .6meters apart. The force between them will be?

Answer 1

The Coulomb's force can be calculated the following ways:

$$F=\frac{1}{4\pi \epsilon_0}\frac{q_1q_2}{r^2}= \\\space\\ \frac{1}{4\pi 8.85\cdot10^{-12}}\frac{(4\cdot10^{-6})(4\cdot10^{-6})}{0.6^2}=0.4\text{ N}.$$