Three identical conducting spheres form an equilateral triangle of side length d = 17.5 cm. The sphere radii are much smaller than d and the sphere charges are qA = -1.91 nC, qB = -5.00 nC, and qC = +9.25 nC. (a) What is the magnitude of the electrostatic force between spheres A and C? The following steps are taken: A and B are connected by a thin wire and then disconnected; B is grounded by the wire, and the wire is then removed; B and C are connected by the wire and then disconnected. What now are the magnitudes of the electrostatic force (b) between spheres A and C and (c) between spheres B and C?