일반물리학 2 — Coulomb's Law: Problem 33

33 A particle of charge 3.00 \(\mu\text{C}\) is separated by 0.120 m from a particle of charge \(-1.50 \mu\text{C}\). (a) What is the magnitude of the electrostatic force between them? (b) What must their separation be to reduce that force by an order of magnitude?