# A Finite Line Charge's Electric Field?

1. Oct 8, 2005

Positive charge Q is distributed uniformly along the x-axis from x=0 to x=a. A positive point charge q is located on the positive x-axis at x=a+r, a distance r to the right of the end of Q.

Problem:
Calculate the x-component of the electric field produced by the charge distribution Q at points on the positive x-axis where x>a (i.e., r>0) in terms of some or all of the variables k, q, Q, a, and r, where $$k=\frac{1}{4\pi\epsilon_0}.$$

I don't know what to do, whether it is to split Q into infinitely small sizes and calculate E field for each small part through an integral or what?!

Where do I get started?

2. Oct 8, 2005

### SpaceTiger

Staff Emeritus
Sounds good to me. How about starting with calculating the x component of the field from a single infinitesmal element? Once you've done this, we can discuss how one might generalize it to an integral.