Pb ab b○ 9c qa

Consider the point charges arranged at the corners and at the center of a square, as depicted in the figure. What is the magnitude of the net coulomb force, in newtons, on the charge q in the figure, given that q = 0.85 microcoulombs, qa = 2.7 microcoulombs, qb = -4.2 microcoulombs, qc = -4.5 microcoulombs, qd = 1.9 microcoulombs. The square is 32 cm on a side.