Fixed potentials

Electricity and Magnetism Level 4

Two hemispheres of radius \(R=30~\text{cm}\) are held at constant potentials \(V_{1}=3~\text{V}\) and \(V_{2}=9~\text{V}\). Determine the electric potential in volts at a point P with coordinates \((x,y,z)=(0,0, 3R)\).