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Homework Help: Rigid body

  1. Oct 9, 2016 #1
    • Member warned that homework questions must include an effort
    1. The problem statement, all variables and given/known data

    An unbalanced pulley 8in. radio. and 32.3 pounds weighing. It has a radius of gyration of 6in with respect to its axis. When a pair M = 100pie.lb applies, lifts a weight W = 96.6 pounds. In the position shown in the figure, the pulley has an angular velocity of 3 rad / sec in counter-clockwise. Determining the tension in the string T and axial components of Ox and Oy, of the reaction in O. Neglect reaction friction and suppose the periphery of the small pulley is smooth. Thanks

    Book results:
    T=141.6 lb
    Ox=-143.7 lb
    Oy=31.45 lb

    2. Relevant equations: (rigid body dynamics)
    ΣT=(ri-R) x (mi ai)

    3. The attempt at a solution
    I try to raise the equations of rigid body dynamics, but I'm nowhere near the result. I think I have to take into consideration the imbalance of the pulley. How should raise the equations? Thanks
  2. jcsd
  3. Oct 9, 2016 #2


    Staff: Mentor

    Whether they are correct or incorrect, please show us what you have tried.
  4. Oct 9, 2016 #3
    I try this:
    T - m.g = m.ay
    T = m(ay + g)
    T = 32,3 (ay + 32,2)
    I need to calculate ay.

    T.6in = IO.α
    6T = (½ . m . r^2).α
    6T=(½ . 32,3 . 6^2) . 3
    T = 289. This result is not correct
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