Identical isolated conducting spheres 1 and 2 have equal amounts of charge and are separated by a distance large compared with their diameters (Fig. 22-20a). The electrostatic force acting on sphere 2 due to sphere 1 is F. Suppose now that a third identical sphere 3, having an insulating handle and initially neutral, is touched first to sphere 1 (Fig. 22-20b), then to sphere 2 (Fig. 22-20c), and finally removed (Fig. 22-20d). In terms of F, what is the electrostatic force F' that now acts on sphere 2? The way I did it, when Sphere1 touches Sphere3, they both end up w/ electrostatic force of 1/2F. Then when Sphere3 touches Sphere2, they distribute evenly to have a electrostatic force of 0.75 F. But this answer is wrong, what did i do wrong?