1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Electrostatics Line Charge question

  1. Feb 3, 2017 #1

    grandpa2390

    User Avatar
    Gold Member

    1. The problem statement, all variables and given/known data
    Find the Electric field a distance z above one end of a straight line segment of length L that carries a uniform line charge λ

    2. Relevant equations
    Complicated formula due to lack of font for the notation used by the author of the book. so I wrote it out. I did my best to differentiate between the script r and pi.

    just in case I did a terrible job, only the first "r" is pi, the rest are script r's

    3. The attempt at a solution

    My professor says during the lecture while doing this problem that the λ is not dependent on r so is a constant and can be pulled out of the integral, but then it also just disappears from the problem completely.

    Why?

    dAlJSvp.jpg

    BTkRP2B.jpg
     
  2. jcsd
  3. Feb 3, 2017 #2

    cnh1995

    User Avatar
    Homework Helper

    Your working is hard to read. It would be better if you typed the equations. You can use LaTeX.
    https://www.physicsforums.com/help/latexhelp/
    It shouldn't.
    You need to first find the horizontal and vertical components of the field separately.
     
  4. Feb 3, 2017 #3

    haruspex

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    Did your professor say that, or is it something you observe? It is still there in your final equation.
     
  5. Feb 3, 2017 #4
    Inside your integral there is a vector and it's magnitude is not 1 (as one can see in the drawing) so this magnitude will be there multiplying the argument and that is not right. You should be carefull when solving the integral.

    Sorry i didn't see the hat over the u. That indicates that it is a unity vector.
     
  6. Feb 4, 2017 #5

    grandpa2390

    User Avatar
    Gold Member

    nvm
    I got it.
     
    Last edited: Feb 4, 2017
  7. Feb 4, 2017 #6

    grandpa2390

    User Avatar
    Gold Member

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Electrostatics Line Charge question
Loading...