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.