1. The problem statement, all variables and given/known data Attached. If you don't mind I'd like to go through each part of the question to make sure I've understood correctly. Thanks a lot 2. Relevant equations F=qE F=(γq^2)/(d^2) F=Kx Taylor/Maclaurin (?) 3. The attempt at a solution So for part (a) I know that Coulomb's interaction, the spring force, and the electric force all act on the particles, so by adding all these force vectors I will obtain the required vector equations. However, I'm not sure on the directions of the forces; why is the electric force F=qE positive for in both vector equations (do they act in the same direction and if so, which?), and why is the restoring spring force opposite for the each of the two? As for the other parts, I don't really know where to begin.