Answer to Question #186891 in Physics for Geovani Clarke

Question

The force between two electrical charges is 0.4 N. What would be the force if the charges are doubled, and the distance between them increased by 100%?

Answer 1

Write the equation for force between "normal" charges:

$$F=k\frac{q_1q_2}{r^2}=0.4\text N.$$

Write the equation for the "modified" system of charges:

$$F_m=k\frac{(2q_1)(2q_2)}{(2r)^2}=k\frac{q_1q_2}{r^2}=0.4\text N.$$