A point charge of +Q is placed at the center of a squa
s7 4e-7z 5pr(r-j pzen;zbrh) m ovhj2re, and a second point charge of -Q is p
74z)7o;- rrp ph5nz( 2ebvsmejzjrh-laced 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?