Walker, Halliday & Resnick — Coulomb's Law: Problem 26

26 In Fig. 21-19a, three positively charged particles are fixed on an x axis. Particles B and C are so close to each other that they can be considered to be at the same distance from particle A. The net force on particle A due to particles B and C is $2.310 \times 10^{-23}$ N in the negative direction of the x axis. In Fig. 21-19b, particle B has been moved to the opposite side of A but is still at the same distance from it. The net force on A is now $2.877 \times 10^{-24}$ N in the negative direction of the x axis. What is the ratio $q_C/q_B$?