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!

De broglie waves

  1. Oct 28, 2005 #1
    for the following question:
    a hydorgen atom is 5.3*10^(-11) m in radius. use the uncertainty principle to estimate the minimum energy an electron acan have in this atom.

    my problem:
    to calculate the kinetic energy, do you use Ek=(p^2)/2m or Ek=pc????
  2. jcsd
  3. Oct 28, 2005 #2
    The uncertainty principal is: /\x/\p = h/2*pi.

    /\x is the radius you have stated.

    /\p is the uncertainty of momentum. p = mv, mass is known, so /\p = m/\v.

    So: /\v = h/(2 * pi * m * /\x)

    where m is the mass of the electron.

    Find /\v, then you can find the minimum energy:

    energy = 0.5 * m * /\v^2.
    Last edited: Oct 28, 2005
  4. Oct 29, 2005 #3
    is that the same as just calculating the kinetic energy=p^2/2m?
  5. Oct 29, 2005 #4
    Yep, that's another way.
  6. Oct 31, 2005 #5
    ok~ that's cool!
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - broglie waves Date
De Broglie wave length Sep 28, 2015
De Broglie Matter Waves Apr 6, 2011
De Broglie/wave problem Feb 16, 2011
De Broglie's Wavelength (matter wave) Jul 27, 2010
Dispersion Relation of a De Broglie Wave Mar 7, 2009