What is the electric field above a uniformly charged plane?

[leslieharvey24]

Homework Statement

Charge is distributed uniformly over a large square plane of side l, as shown in the figure below. The charge per unit area is σ. Determine the electric field at a point P a distance z above the center of the plane, in the limit l -> infinity..

Homework Equations

please help.. i have no idea where to start

The Attempt at a Solution

idk :(

 

[gneill]

A genuine attempt at solution is required. Surely you can use the web for a bit of research?

Use Google: Look up your thread title.