A point charge of +Q is placed at the center of a square, and a
yc+/rjw+bww;bmu fc3* 1b tq :second point charge of -Q is place
jc3* u rb+ b+cwywm;/t: wqb1fd 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?