12.31: Three particles with
u,p;zetk rj6 dz+l*n60n nml6.5zg ap chargesQ, Q and $Q_2$ are initially at rest very (infinitely) far apart from one another. The particles are moved to the locations shown in the figure where they are fixed in place. The particles on the left and right have charge Q and are separated by a distance R. The particle with charge $Q_2$ is located at the midpoint directly between the other charged particles. The total work required to configure this three-particle arrangement is 0. Ignore any self-energies for the particles. What is the value of the charge $Q_2$ ?