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

Drude formula

  1. Feb 5, 2014 #1
    I can't derive it properly even though it should be easy:
    From Newtons 2nd law:

    m dv/dt = -eE

    =>

    v(t) = -meEt + v(0) (the latter will average out when taking average)

    Now the Drude assumption: An electron will on average travel a time τ before being scattered and starting its motion in the direction of E all over.

    Thus this means, I think, that on average an electron will travel with a velocity equal to
    <v> = -meEτ/2

    And one can then multiply by electron density to get the Drude formula. Problem is the conductivity should not have the factor ½. Am I not right in thinking that the electron on average will travel at the velocit given above.
     
  2. jcsd
  3. May 29, 2014 #2
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook




Loading...
Similar Threads for Drude formula
I How is this formula for the speed of sound derived?