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Rotational motion of a solid sphere of mass

  1. Dec 6, 2011 #1
    A solid sphere of mass m is released from rest from the rim of a hemispherical cup so that it rolls along the surface. If the rim of the hemisphere is kept horizontal, find the normal force exerted by the cup on the ball when the ball reaches the bottom of the cup.
  2. jcsd
  3. Dec 7, 2011 #2
    This sounds suspiciously like a homework question... anyway, the bottom of the cup is horizontal so the normal force must be equal and opposite to the weight of the ball, ie. acting upwards and of magnitude m*g.
  4. Dec 7, 2011 #3

    Doc Al

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    Staff: Mentor

    Yep. It belongs in the Intro Physics forum.
    No, the rim of the cup is kept horizontal.
    Last edited: Dec 7, 2011
  5. Dec 7, 2011 #4


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    Science Advisor

    Okay, so the tangent plane to the bottom of the cup is horizontal?
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