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Homework Help: Yoyo is released from rest

  1. Jun 27, 2010 #1
    1. The problem statement, all variables and given/known data
    A yoyo with a mass of m = 179 g is released from rest as shown in the figure.

    https://s6.lite.msu.edu/res/msu/nagytibo/Mechanics/Rotation/Graphics/001a.gif" [Broken]

    The inner radius of the yoyo is r = 2.60 cm, and the outer radius is R = 3.60 cm, and the moment of inertia about the axis perpendicular to the plane of the yoyo and passing through the center of mass is ICM = 9.70×10-5 kgm2.
    1.Determine the linear acceleration of the yoyo.
    2. Determine the angular acceleration of the yoyo.
    3.What is the weight of the yoyo?
    4.What is the tension in the rope?
    5.If a 1.04 m long section of the rope unwinds from the yoyo, then what will be the angular speed of the yoyo?
    2. Relevant equations

    These are the equations I believe to be correct. However, they are not working out.
    1) a = g*[1 - I/(mr²+I)]
    2) α = a/r
    3) W = m*g
    4) T = g*I*m/(mr²+I)
    5) w = v/r = √(2ay)/r

    3. The attempt at a solution
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Jun 27, 2010 #2


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    The figure is not accessible to us. Also, please show how you got the equations that you believe to be correct, then we might be able to point out where you went wrong.
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