# Calculating the Electric Field generated by a rod with charge

• jmarzouq
In summary, the problem involves finding the electric field at a point p above the center of a rod with a length of 2L and charges of -Q on the left half and +Q on the right half. The electric field can be calculated using the formula E= 1/(4pi\epsilon_{0})∫dq/r(\hat{r}), where dq is the charge per unit length and the distance from the rod to point p is √(L2+z2). To find the electric field due to the entire rod, integration is required.

## Homework Statement

A rod of length 2L has a charge -Q uniformly distributed over its left half and +Q uniformly distributed over its right half. Find E at point p a distance z above the center of the rod.

## Homework Equations

E= 1/(4pi$\epsilon$$_{0}$)∫dq/r($\hat{r}$)
dq=λdl

where $\epsilon$$_{0}$= 8.854 x 10-12 C2/Nm2
and λ=charge per unit length

## The Attempt at a Solution

I'm not even sure where to start exactly. I know the length from the rod to p at any given point will be √(L2+z2) but I'm really not sure where to go from here. I missed a couple of class periods due to being sick and I've been trying to play catch up ever since so any help would be greatly appreciated!

Find the field dE at the point p due to symmetrically placed charged element with opposite charge. Resolve dE into two components and find the resultant field dE. To find the field due to whole rod, find the integration.

That's the thing. I'm at a loss as to how to do that exactly. The only thing I've been able to calculate the electric field for is point charges. Like I said, I've missed a couple of days and really have no idea what to do. I'd imagine you'd use Gauss's law, I just don't know how to go about doing it exactly.