Two identical metal balls with charges +2Q and -Q are seperated by some distance, and exert a force F on each other. They are joined by a conducting wire, which is then removed. The force between them will now be:

Explanation

When the two identical metal balls are connected by a conducting wire, charge redistribution occurs. The total charge becomes (2Q - Q) = Q. Since the balls are identical, the charge is equally distributed, giving each ball a charge of Q/2. The force between two charges is given by Coulomb's law, F = k * (q1 * q2) / r². Originally, the force was F = k * (2Q * -Q) / r². After redistribution, it becomes F' = k * ((Q/2) * (Q/2)) / r². Simplifying F', we get F/8. Therefore, the correct answer is F/8. The other options are incorrect because they do not account for this redistribution and subsequent recalculation of the force.