Chapter 8, Problem 8.3E

Two small metallic bodies are given opposite charges, with the negatively charged body having twice the charge of the positively charged body. They are immersed in water (dielectric constant $=78$) at a distance of $6.075\text{cm}$, and it is found that the force of attraction between the two metal pieces is $1.55\times {10}^{-6}\text{N}$. (a) What are the charges on the pieces of metal? (b) What are the electric fields of the two bodies?