Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Hollow sphere rolling up a ramp

  1. Feb 4, 2009 #1
    1. The problem statement, all variables and given/known data
    a hollow sphere is rolling long a horizontal floor at 5 m/s when it comes to a 30 degree incline. how far up the incline does it roll before reversing direction?


    2. Relevant equations



    3. The attempt at a solution
    it seems like conservation of energy would work best for this problem
    1/2mv^2 + 1/2I[tex]\omega[/tex]^2 = mgh
    im just having some problems finding [tex]\omega[/tex]
    am i doing this right? and if so any clues on how to find [tex]\omega[/tex]?
    thanks in advance
     
  2. jcsd
  3. Feb 4, 2009 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Assuming the sphere is rolling without slipping, ω and v are directly related. (What's the condition for rolling without slipping?) What's the rotational inertia of a hollow sphere?

    Your method is fine.
     
  4. Feb 4, 2009 #3
    v=[tex]\omega[/tex]r right? but we dont have the radius of the sphere
    or do we.................?
     
  5. Feb 4, 2009 #4

    Doc Al

    User Avatar

    Staff: Mentor

    Right.
    Maybe you don't need it. :wink: (Just call it "r" and see what happens.)
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook