2 light conducting spheres,each with 6mm diameters and having a mass of 10mg are suspended from the same point by fine insulating fibres 50cm long.

2 light conducting spheres,each with 6mm diameters and having a mass of 10mg are suspended from the same point by fine insulating fibres 50cm long.due to electrostatic repulsion the spheres are in equilibrium when 3cm apart. what is ;the charge on each sphere andthe potential on each sphere?