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Last Activity: 7 Years ago
Its "0" because Q is equidistant from all four point and it cancels out and we get "0" okay assume the square and Q as a charge on pillar on centre the distance of end of the pillar from points is "2 s power half a"then now we want distamce of top of pillar from points now we can see aright angle triangle of pillars hiegjt h and base "2 s power half a" and we have the hypotneuse equal from both points and then they all cancel out because this force is vector