# Two small metal spheres A and B (of the same size) are each given a charge q. They are placed in the air and are separated by a distance r. A third similar metal sphere C is touched with the sphere A and is placed midway on the line joining the two spheres A and B.What is the force acting on the sphere A?

The force acting on the sphere A =$3q^2/(8 \pi \in_0 r^2)$