Four lightweight, plastic spheres, labeled A, B, C, and D, are suspended from threads in v...

Four lightweight, plastic spheres, labeled A, B, C, and D, are suspended from threads in various combinations, as illustrated in Figure 19−37. It is given that the net charge on sphere D is +Q, and that the other spheres have net charges of +Q, −Q, or 0. From the results of the four experiments shown in Figure 19−37, and the fact that the spheres have equal masses, determine the net charge of (a) sphere A, (b) sphere B, and (c) sphere C.

Figure 19−37 Problem