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Sphere rolling down a ramp

  1. Jul 23, 2009 #1
    1. The problem statement, all variables and given/known data
    A solid sphere of uniform density (weight = 3.2 lbs starts from rest and rolls down a ramp (H = 1.57 m, q = 18.3°.)

    Find the speed of the sphere's CM when it reaches the bottom of the ramp.

    haha sorry bout that....

    2. Relevant equations

    see below

    3. The attempt at a solution
    i dont' know whats wrong with my set up here,
    m*g*d*sin(theta) = .5mv^2 + (2/5)(.5)mv^2

    any help?

    Last edited: Jul 23, 2009
  2. jcsd
  3. Jul 23, 2009 #2


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    It might help if we knew what the question was!
  4. Jul 23, 2009 #3
    Ops... forgot to add the question. silly me >.<
  5. Jul 23, 2009 #4


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    Your conservation of energy equation looks wonky. If I'm doing this right, you should have that m*g*h = (0.5)mv2 + (2/5)*(0.5)mv2. You're already given the height of the ramp!
  6. Jul 23, 2009 #5
    i hate when they put extra information in it, you just feel obligated to use it.

    yes your right, thanks alot for the help!
  7. Jul 23, 2009 #6


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    You're welcome! :)
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