In a precision nanotechnology experiment, two small metal spheres are held at a fixed distance r r\,r from one another. Initially, they carry positive static charges of +2Q+2Q+2Q and +8Q+8Q+8Q respectively, resulting in a repulsive electrostatic force of magnitude F F\,F between them.
An equal charge of −5Q-5Q−5Q is now transferred to each sphere, with the separation distance r r\,r remaining unchanged.
Determine the magnitude of the new electrostatic force between the spheres in terms of FFF, and state whether this new force is attractive or repulsive. Fully justify your answer.