1. Not finding help here? Sign up for a free 30min 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!

Thin Rod + Poncual Charge Find Vb-Va

  1. Oct 1, 2008 #1
    Thin Rod + Poncual Charge.... Find Vb-Va

    1. The problem statement, all variables and given/known data
    A thin "rod" of 10 m is located between (0m,4m) and (0m,14m). Its linear density is 50*10^-9C/m. Also, there is a ponctal charge of Q=10*10^-9 located at (-1m,0m).
    Given 2 points:
    A at (0m,-5m)
    B at (0m,0m)
    Find Vb-Va.

    2. Relevant equations
    some integrals...

    3. The attempt at a solution
    Okay, this seems like a tricky one, does it not?
    I know I could use Vb-Va = Integral of : E*s, possibly with s=5
    But then, I would have a Vb-Va for the rod, would I have to also calculate the Vb-Va due to the poncyal charge and then sum these 2? This is what I would have done during an exam, though I'm really not sure it'd be good, would it?

    Thanks for any help you can provide... belive me, I,ve tried it a couple of times before posting here.:wink:
  2. jcsd
  3. Oct 1, 2008 #2
    Re: Thin Rod + Poncual Charge.... Find Vb-Va

    Ok, so i've tried something, not sure though...
    I could separate the question in finding :
    -Vb : Vb-from the rog + Vb from the charge
    -Va : Va-from the rog + Va from the charge
    And then simply substract...is this it? Im not sure but i just think it could...

    Thanks for helping
  4. Oct 2, 2008 #3
    Re: Thin Rod + Poncual Charge.... Find Vb-Va

    I managed to find a number, but as I do not have the answer key, i can't tell if it's good. So if somebody is able to do it, maybe then we could compare our answers :)
    this would be really appreciated
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?