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Homework Help: No idea please help.

  1. Nov 28, 2007 #1
    This is yet another sample exam problem which I don't quite know how to approach. Any help would be greatly appreciated.

    5) Consider an object of mass m that moves in a circular orbit caused by a central
    force given by F=-kr, where k is a constant. Suppose that the Bohr quantization
    condition (L=mvr=nh) is applied to this motion. What are the allowed radii?
    a. rn=(n4h4/m2k)1/4, n = 1,2,…
    b. rn=(n2h2/mk)1/4, n = 1,2,…
    c. rn=(n2h2/mk)1/3, n = 1,2,…
    d. rn=(n2h2/mk)1/2, n = 1,2,…
    e. Not enough information given to compute levels
    f. Radii for this force law cannot be quantized
  2. jcsd
  3. Nov 28, 2007 #2


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    Science Advisor

    You first find v by requiring the force to produce the centrepital acceleration of circular motion. Then set L=mvr=nh and solve for r.
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