Physics
posted by Niraj .
A,B,C,D are four charges placed at each corner of a square, with A= 6.00 mC , B=6.00 mC, C=6.00 mC and D=6.00 mC.ALso AB=BC=CD=DA=0.100 m.Determine the magnitude and direction of force on each charge.

Each charge experiences an attraction to the two nearest corners and a repulsion (half as large) from the farthest corner. When the forces from the two nearest corners are added as vectors, the resultant is along the diagonal. When you add up the three forces from the other three corners as vectors, they should cancel out.