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Homework Help: Need help on uncertainty principle

  1. Nov 13, 2008 #1
    1. The problem statement, all variables and given/known data
    In order for a neutron can exist in a nucleus, its wavelength must be smaller than the size of the nucleus (say 2 x 10-15 m)
    Use the uncertainty principle to calculate and show that a neutron would have a kinetic energy much smaller than its rest mass energy

    2. Relevant equations

    ΔE Δt > h/4π

    3. The attempt at a solution

    I had no clue in how to solve this problem. At first, I was thinking to solve for E, but figured that I don't know how to calculate for t.

    Can anyone help me with this question?
  2. jcsd
  3. Nov 14, 2008 #2


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    Staff Emeritus
    Science Advisor
    Homework Helper

    There's another version of the uncertainty principle, involving position and momentum. Try that.

    p.s. welcome to PF.
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