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Homework Help: Particle of mass m in a box of length L Quantum Mechanics

  1. Mar 1, 2010 #1
    1. http://img10.imageshack.us/img10/8602/232cw.jpg [Broken]/b][/URL]

    2. Relevant equations
    http://img199.imageshack.us/img199/484/232ag.jpg [Broken]

    sorry about the insert pictures, i dont know how to type up the eqns easily

    3. The attempt at a solution
    Now I know that outside the box the schrodinger equation should give 0 right. I'm just not sure how to go about (a) and (b). (c) The expectation value is pretty straightforward in that you just evalutate <psi|omega|psi>/<psi|psi> with the boundaries from 0 to L and we know the denominator here is 1 since it's normalized.
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Mar 1, 2010 #2
    I think for part(a) .. you have to solve the schroedinger`s equation to obtain the energy and you know that the potential inside the box is zero , so go from there ..
  4. Mar 1, 2010 #3


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    Gold Member

    One fundamental postulate of QM is that if you make an observation, then you collapse the state of the particle into an eigenstate of the observable. Eigenstates of the Hamiltonian (the energy observable) are exactly the solutions to the Schroedinger equation. From this information, can you see what are the possibilities when you measure the energy of the system?
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