College Physics 10th Edition by Raymond Serway,Chris Vuille

Exercise 72

Two metal balls A and B of negligible radius are floating at rest on Space Station Freedom between two metal bulkheads, connected by a taut nonconducting thread of length 2.00 m. Ball A carries charge q , and ball B carries charge 2 q. Each ball is 1.00 m away from a bulkhead. (a) If the tension in the string is 2.50 N, what is the magnitude of q (b) What happens to the system as time passes Explain.