4.61 With reference to Fig. P4.61, charge Q is located at a distance d above a grounded half-plane located in the x-y plane and at a distance d from another

grounded half-plane in the x-z plane. Use the image method to (a) Establish the magnitudes, polarities, and locations of the images of charge Q with respect to each of the two ground planes (as if each is infinite in extent). (b) Find the electric potential and electric field at an arbitrary point P = (0,y,z).