A point charge of +Q is place
xn-0,x1hacexu,a zs9fm7c)3g m .zce*0jcw gd at the center of a square, and a second point charge of
aa -cx, m)ze3g9x w 0cmjsg*fz. e,n7huc 1x0c-Q is placed at the upper-left corner. It is observed that an electrostatic force of 2.0 N acts on the positive charge at the center. What is the magnitude of the force that acts on the center charge if a third charge of -Q is placed at the lower-left corner?