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!

De Broglie problem

  1. Mar 11, 2008 #1
    1. The problem statement, all variables and given/known data
    What is the length of a one-dimensional box in which an electron in the n=1 state has the same energy as a photon with a wavelength of 500 nm


    2. Relevant equations


    E=h^2/8mL^2 and E=hc/lambda

    making it
    L=sqrt( (h*lambda)/(8cm) )


    3. The attempt at a solution

    I plugged in for those numbers and did not come out with the correct number. any suggestions?
     
  2. jcsd
  3. Mar 14, 2008 #2
    Are you sure that 8 should not be a 4?
     
  4. Mar 14, 2008 #3

    pam

    User Avatar

    The eightfold way is right here. 1/8=(L/2)^/2.
    I think your first h should be hbar.
     
  5. Mar 21, 2008 #4
    Hey
    The energy if the first state of an indefinite one-dimensional box is:
    [tex]E=\frac{\pi^{2}\hbar^{2}}{2mL^{2}}[/tex]
    Where m is the mass of the particle and L is the length of the box.
    The photon has the energy given by
    [tex]E=\hbar\omega=\frac{2\pi\hbar{c}}{\lambda}[/tex]
    Where [tex]\lambda[/tex] is the wave length.
    And therefore the length L is [tex]L=\sqrt{\frac{\pi\hbar\lambda{c}}{4m}}[/tex]
     
    Last edited: Mar 21, 2008
  6. Mar 26, 2008 #5

    Shooting Star

    User Avatar
    Homework Helper

    Which is wrong. It should be [tex]\sqrt{\frac{\pi\hbar\lambda}{4mc}[/tex], which is identical to what the OP psingh had written correctly. Replacing [itex]h[/itex] by [itex]2\pi\hbar[/itex] won't do any good.

    Perhaps the OP made some arithmetical mistake...
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: De Broglie problem
  1. De Broglie/wave problem (Replies: 11)

  2. De broglie wavelength? (Replies: 1)

  3. De broglie wavelength (Replies: 2)

Loading...