Question: Two identical conducting spheres, fixed in place, attract each other with an electrostatic force of 0.141 N when their center-to-center separation is 67.0 cm. The spheres are then connected by a thin conducting wire. When the wire is removed, the spheres repel each other with an electrostatic force of 0.0528 N. Of the initial charges on the spheres, with a positive net charge, what was (a) the negative charge in coulombs on one of them and (b) the positive charge in coulombs on the other? I got the right answer, however I am confused on one of the first steps. I say q1 will be positive and q2 will be negative and Columbs law is set like this: Code (Text): F=-(k*q1*q2)/r[SUP]2[/SUP] My question is why is this negative and for qfinal it is positive when setting up Columbs law. I hope I was clear enough in this question.