Question

Two point electric charges q2 = 5q1 and q1 are at a distance of 3 meters and apply a repulsive force of 0.02 N to each other, and how many microclones?

Answer 1

The Coulomb's law says

$$F=k\frac{q_1q_2}{r^2}=k\frac{5q_1^2}{r^2}$$

Hence

$$q_1=\sqrt{Fr^2/(5k)}\\ =\sqrt{0.02*3^2/(5*9*10^9)}=2*10^{-6}\:\rm C=2\:\mu C$$

$$q_2=5q_1=5*2\:\mu C=10\:\mu C$$