Determine the electrostatic potential energy of a system consisting
of two charges $7 \mu C$ and $–2 \mu C$ (and with no external field) placed
at $(–9 cm, 0, 0)$ and $(9 cm, 0, 0)$ respectively.mple 2.5
(a) Determine the electrostatic potential energy of a system consisting
of two charges 7 µC and –2 µC (and with no external field) placed
at (–9 cm, 0, 0) and (9 cm, 0, 0) respectively.Suppose that the same system of charges is now placed in an
external electric field $E = A (1/r^2); A = 9 \times 10^5 C m^{–2}$. What would
the electrostatic energy of the configuration be?
