Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Coulomb Constant Question

  1. Feb 6, 2008 #1
    1. The problem statement, all variables and given/known data
    I'm sure I'm missing something simple here, but to the point:

    I calculate the electric field a distance r from a uniform straight infinite line charge using Gauss' Law and get an answer; I do the same calculation using Coulomb's law and get the same answer but a pi remains in the denominator (that was not there in the Gauss' Law solution). I don't know how to enter the equation here, but in both answers the numerator is the linear charge density. The Gauss' Law denonminator is 2r times epsilon; Coulomb's law denominator is 2(pi)r times epsilon. Help!


    2. Relevant equations
    See above


    3. The attempt at a solution
    See above
     
  2. jcsd
  3. Feb 6, 2008 #2
    Can you write out each of your steps? Maybe then one of us'll be able to spot the error.
     
  4. Feb 6, 2008 #3
    Well, thanks for the fast response. In writing out the steps as you requested I caught a (dumb) integration error - I'm straight now. Thanks.
     
  5. Feb 6, 2008 #4
    You can't imagine how many times I've been stumped on a problem only to realize my error while explaining what I did to someone. :)
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook