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Homework Help: Mechanics: Statics problem

  1. Feb 13, 2008 #1
    1. The problem statement, all variables and given/known data

    Determine and locate the resultant R of the two forces and one couple acting on the I beam.



    I understand this is kind of hard to understand this is the best I could do "====" = 3 ft
    first | = 6kN force upwards
    O= couple 52kN m ccw
    second | = 10kN downards

    2. Relevant equations

    3. The attempt at a solution

    I chose to move all the forces to b where the couple was so that I wouldn't have to wry about the force caused by said couple when finding the resultant. The resultant would then be 4kN down at 6m. However the book says the answer is 4kN down at 5m I am really confused can somebody please help me if you need more help to understand the question please ask.
    Last edited: Feb 13, 2008
  2. jcsd
  3. Feb 14, 2008 #2


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    You did a good job explaining the problem. But I am not sure what you mean by moving the forces to b. The resultant force must be 4kN down as you noted, but you must correctly determining its location by first summing moments about any point, including the couple, (which just adds or subtracts from the moments of the forces), then solve for the distance the 4kN resultant must be from that point in order to get the same summed moments.
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