A point charge of +Q is placed at the center of a
g;7we07xxolb square, and a second point charge of -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
xxbo7ewg0 l;7a third charge of -Q is placed at the lower-left corner?