Point charge Q1 = -2 nC, Q2 is = 1 nC, the Q3 = 1 nC located on the plane in the lattice sites to the cell in the form of a square with sides of 0.1 m. The lattice sites, which are referred to the charges set radius vectors r1 = (a, 0), r2 = (- a, a), r3 = (- a, -a). The remaining nodes are no charges. Determine the dipole moment of the system of charges and their potential energy in an external electric field E = (100,0) V / m.

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