Calculating Charges of Identical Tiny Conducting Spheres

[fresheze13]

Homework Statement

You have two identical tiny conducting spheres: sphere A carries positive charge qA, and sphere B carries negative charge qB. First the spheres are placed distance d = 0.404 m apart, and they attract each other with a force F1 = 0.748 N. Then the spheres are brought together, touch each other, and are brought back to distance 0.404 m apart. Now the spheres are both positive, and they repel each other with force F2 = 0.59 N. Find the original charge on each sphere.

Homework Equations

F=k q1q2/r^2

The Attempt at a Solution

after the spheres touch i get qf=(q1+q2)/2
and i solve for the charge on the spheres after they touch and get .1035uC as my answer but I am not sure how to find original charge after that my proffesor never did an example like this any help is welcome and appreciated

 

[Fightfish]

Charge is conserved. Make use of that along with F1.
Besides, this belongs in the introductory physics section.