(a) The above figure (a) shows a nonconducting rod of length L=6.00cm and uniform linear charge density λ=+3.68pC/m. Assume that the electric potential is defined to be V=0 at infinity. What is V at point P at distance d=8.00cm along the rod's perpendicular bisector? (b) Figure (b) shows an identical rod except that one half is now negatively charged. Both halves have a linear charge density of magnitude 3.68pC/m. With V=0 at infinity, what is V at P?