일반물리학 2 — Coulomb's Law: Problem 7

7 In Fig. 21-12, particle 1 of charge \(q\) and particle 2 of charge \(9.00q\) are held at separation \(L = 8.00 \text{ cm}\) on an x axis. If particle 3 of charge \(q_3\) is to be located such that the three particles remain in place when released, what must be the (a) x and (b) y coordinates of particle 3, and (c) the ratio \(q_3/q\)?