### Electric Potential

A
charge per unit length l is distributed uniformly along a thin rod of length L.
(a) Determine the potential (chosen to be zero at infinity) at point P a
distance y from one end of the rod and in line with it (see Fig. 28-45
below). (b) Use the result of (a) to compute the component of the electric
field at P in the y direction (along the rod). (c) Determine the component of the electric
field at P in a direction perpendicular to the rod.