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

Homework Help: The uncertainty principle

  1. Sep 26, 2010 #1
    A particle is confined within a spherical radius of one femtometer(10^-15 m)?

    Its momentum can be expected to be about-
    1. 20 keV/c
    2. 200 keV/c
    3. 200 MeV/c
    4. 2 GeV/c

    How should I go about using HUP on a problem like this one? I tried substituting x=10^-15 meters in px=h/4 pi but the answer is wrong. Apparently because the problem is about volume.
  2. jcsd
  3. Sep 26, 2010 #2
    We can only estimate the magnitude order of it; the answer is no way precise. Just pick the answer which is nearest to your answer.
    By the way, the uncertainty in x-coordinate is 2R, not R.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook