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Homework Help: Energy of a Rolling Object

  1. Nov 15, 2007 #1
    1. The problem statement, all variables and given/known data

    A solid sphere of mass 0.599 kg rolls without slipping along a horizontal surface with a translational speed of 5.31 m/s. It comes to an incline that makes an angle of 33° with the horizontal surface. Neglect energy losses due to friction.

    (a) What is the total energy of the rolling sphere?
    ________ J
    (b) To what vertical height above the horizontal surface does the sphere rise on the incline?
    ________ m

    2. Relevant equations


    3. The attempt at a solution

    What equations would I use for this problem? any other information would be great thanks!
  2. jcsd
  3. Nov 15, 2007 #2


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    You can't find ANY equations?
  4. Nov 16, 2007 #3
    Kinetic energy is given by [tex]K=\frac{1}{2}mv^2[/tex]

    Rotational energy is given by [tex]T=\frac{1}{2}I\omega^2[/tex]

    The moment of intertia for a solid sphere is given by [tex]I=\frac{2}{5}mr^2[/tex]

    Potential energy is given by [tex]U=mgh[/tex]
  5. Nov 16, 2007 #4
    You will need one more equation to solve this.

    [tex]v=\omega r[/tex]
  6. Nov 16, 2007 #5
    Some hints from a fellow learner:

    - How do you calculate linear (aka translational) movement energy for a body?
    - What is the difference between kinetic and potential energies and how do you calculate them?
    - Is energy conserved, if there is no friction or drag (aka energy losses)?
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