Introduction to Electrodynamics · Problem 2.37

Electrostatics — David J. Griffiths

Physics · interaction-energy-two-point-charges

Problem

Find the interaction energy (

\epsilon_0 \int \mathbf{E}_1 \cdot \mathbf{E}_2 \, d\tau

in Eq. 2.47) for two point charges,

q_1

and

q_2

, a distance

a

apart. [Hint: Put

q_1

at the origin and

q_2

on the

z

axis; use spherical coordinates, and do the

r

integral first.]