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Homework Help: 3 dimension reactions problem - statics

  1. Nov 13, 2013 #1
    1. The problem statement, all variables and given/known data
    A 100-kg uniform rectangular plate is supported in the position shown by hinges A and B and by cable DCE that passes over a frictionless hook at C. Assuming that the tension is the same in both parts of the cable, determine (a) the tension in the cable, (b) the reactions at A and B. (assume that the hinge at B does not exert any axial thrust)

    2. Relevant equations

    3. The attempt at a solution
    What does it mean when it says assume that the hinge at B does not exert any axial trust?
    Everyone keeps telling me that it means that there's no reactions, yet in the free body diagram, I see reaction forces, just no reaction moments, is this what it means?

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  3. Nov 14, 2013 #2
    I don't know, but would guess (and proceed on the assumption that) it means no reaction component parallel to AB.
  4. Nov 14, 2013 #3


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    It means at hinge B, there will be reaction forces in the direction of the y-axis and z-axis. It's a hinge, so it can't support a reaction moment about the x-axis.

    I think the stipulation about hinge B not being able to support an axial reaction force is to ensure that the problem is statically determinant.
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