Question

Two fixed indentical conducting spheres, attract each other with an electrostatic force of 0.108N when their center-to-center seperation is 50.0cm. The spheres are then connected by a thin conducting wire. When the wire is removed, the spheres repell each other with an electrostatic force of 0.0360N. Of the initial charges on the spheres, with a positve net charge, what was (a) the negative charge on one of them and (b) the positive charge on the other?

Answer 1

Initial attraction tells you that the charges are different on each sphere, say Q1 and Q2, (positive and negative) and when the spheres are connected the charges flow until both the spheres have the same charge; (Q1+Q2)/2 on each. Use Coulomb's law and form two equations, then solve for Q1 and Q2.

Answer 2

Remember that whatever answers you get for Q1 and Q2, one of them has to be negative and the other positive.

Answer 3

Thanks guys :D

Answer 4

You are welcome :)