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Uncertainity Problem

  1. Nov 21, 2003 #1
    Hi dear virtual friends,

    I am now going to ask you something. I would be pleased if you would answer me.

    In an exam I was asked to show that for a particle in a box of width length L , delta (x)delta(p)>=h/(4*pi) holds.
    I think this is not a logical question. Because I think it is like asking something like this: Prove A using A.

    I would be really grateful if you would write something regarding this.
    Thank you.

    P.S. My problem is not envolving you in doing my homework. I just wanted to know if what I think is right or wrong.
  2. jcsd
  3. Nov 21, 2003 #2
    i think you were supposed to calculate Δx and Δp separately, then multiply the two together, and compare it to h/4pi.

    you know, find the expectation value of x, and then the expectation value of x2 and all that jazz.

    of course you are not allowed to use the Heisenberg Uncertainty principle to show that the Heisenberg Uncertainty principle is true. that is circular.
  4. Nov 23, 2003 #3
    Thank you very much for youranswer.
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