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!

Potential at a point

  1. Sep 22, 2011 #1
    1. The problem statement, all variables and given/known data

    The work done in bringing a charge +q from infinity in free space to a postion at a distance D in front of a semi-infinite grounded metal surface?

    3. The attempt at a solution
    Actually i know the method to solve it, but didn't understand its logic.
    F=[-1/(4pi*e0)](q*-q)/(2d*d)
    When we integrate this F as integral of F.dr between the limits x= d and x= infinity we get the result.
    my question is what is this semi infinte grounded metal? how does this (2d*d) appear in the denominator? des this q and -q appears because of induction charging ?
     
  2. jcsd
  3. Sep 23, 2011 #2
    Isn't this the http://en.wikipedia.org/wiki/Method_of_image_charges" [Broken]?

    Dont' know what's meant by a "semi-infinite" grounded metal though.

    Maybe it's metal taking up half of all available space, and having a plane surface, like http://upload.wikimedia.org/wikipedia/commons/4/4c/Method_of_mirror_images.png" [Broken]. In that case, yeah the -q would be the induced charge. But it looks to me like it would be ((2x)*(2x)) instead of (2d*d) in the denominator, where x is the variable distance of the charge +q from the surface as it moves.
     
    Last edited by a moderator: May 5, 2017
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook