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!

Momentum in Quantum Mechanics

  1. May 2, 2006 #1
    Problem 1.17 in griffiths gives, at time t = 0, the state psi =A(a^2-x^2) for -a to a, and 0 otherwise. It asks then to find the expected value of momentum p at 0 and also the uncertainty in p. How do I do this? The only way momentum is defined is md<x>/dt, and since the state is only for time t, there seems to be no way to do this.

    I know that if i take fourier transform the wave function i'll get the expected momentum, but I don't think that's what the problem wants me to do. Is there a simpler way?
  2. jcsd
  3. May 2, 2006 #2
    never mind, i'm an idiot.
  4. May 2, 2006 #3

    Tom Mattson

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Glad we could help. :biggrin:
  5. May 3, 2006 #4
    :rofl: :rofl: :rofl:
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Momentum in Quantum Mechanics