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!

Finding maximum in Planck's law

  1. Sep 11, 2010 #1
    1. The problem statement, all variables and given/known data
    At what wavelength is u(lambda) a maximum for a star with a surface temperature of 50,000 K?


    2. Relevant equations
    Planck's law
    u(lambda)=8(pi)hc/(lambda^5*(e^(hc/kTlambda)-1)

    3. The attempt at a solution
    I think the maximum is where the derivative of the function u(lambda)=0, but the derivative is too messy to solve in terms of lambda so I can't find the wavelength. So I think I'm way off as far as how to solve it. Any help would be appreciated.
     
  2. jcsd
  3. Sep 12, 2010 #2
    well, the differentiation should be done in order to get \lambda at maximum energy density. The differentiation isn't too hard, try using the product rule first.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Finding maximum in Planck's law
  1. Planck's Law Problem (Replies: 7)

  2. Planck's law (Replies: 11)

  3. Planck Black-Body Law (Replies: 1)

Loading...