Question

Electric charge charge is distributed uniformly along a thin rod of length "a", with total charge Q. Take the potential to be zero at infinity find the potential at P. If z>>a, what would be the potential at p? From potential find the electric field at point p for z>>a.

Answer 1

Note:
P is located above the middle of a, a distance of z

P
(distance vertical z)
___________________
[-------a---------]

Answer 2

http://web.mit.edu/8.02t/www/materials/StudyGuide/guide02.pdf