Two particles each with charge +2.68 µC are located on the x axis. One is at x = 1.00 m, and the other is at x = −1.00 m.

(a) Determine the electric potential on the y axis at y = 0.660 m.
(b) Calculate the change in electric potential energy of the system as a third charged particle of -3.66 µC is brought from infinitely far away to a position on the y axis at y = 0.660 m.