Two fixed identical conducting plates `(alpha and beta)`, each of surface areas S are charged to -Q and q, respectively, where Q>q>0. A third identical plate (y), free to move is located on the other side of the plate which charge q at a distance d. The third platea in released and colides with the plate `beta`. Assume the collision is elastic and the time of collision is sufficient to redistribute charge amongest `beta` and `gamma`.
Find the charges on `beta` and `gamma` after the collision.