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Homework Help: Torque and center of mass question

  1. Mar 11, 2009 #1
    1. The problem statement, all variables and given/known data
    A baseball player holds a 36-ounce bat (weight = 10.0 Newton) with one hand at the point O. The bat is in equilibrium. The weight of the bat acts along a line 60 centimeters to the right of O. What is the torque exerted on the center of mass of the bat by the player?

    2. Relevant equations

    3. The attempt at a solution
    I don't understand it
  2. jcsd
  3. Mar 11, 2009 #2


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    Homework Helper

    Is there a picture associated with your problem?
  4. Mar 11, 2009 #3


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    You say the bat is in equilibrium? I don't see why the player would be exerting any torque on the bat.
  5. Mar 11, 2009 #4
    Based on this and some of your other posts, it sounds like you need to read up on torques.

    http://en.wikipedia.org/wiki/Moment_(physics [Broken])

    If you have a bat held at one end, like a cantilevered beam, the weight of the bat is not acting through the location of the support. In your problem, it tells you that the weight is acting through a point that is 60 cm away from the bat. Presumably, since no angle is given, the bat is horizontal and the angle between your position and force vectors is 90 degrees (which can simplify the problem a little bit).

    In this case, the reaction at the baseball player's hand will consist of a force and a torque to keep the bat in equilibrium.

    Does this help at all?

    At what level are you studying?

    Last edited by a moderator: May 4, 2017
  6. Mar 11, 2009 #5
    The origin is the end of the bat so its acting 60 centimeters away from the origin. Just clarifying.
  7. Mar 11, 2009 #6
    Yes - thanks for the clarification, wesDOT. I should have said that the weight is acting 60 cm away from the baseball player's hand.

  8. Mar 11, 2009 #7

    That is the image he should have posted
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