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[Trusses] Problem finding forces in members

  1. Nov 24, 2014 #1
    Can anyone please explain where does 5/sqrt29 and 3/sqrt34 come from? I already got BC/know how to find BC, but in my own method, I tried to use moment about A or B, knowing that there is HGx, HGy & HCy, HCx -- there are way too many unknowns @ H.

    So, looking at this, I'm wondering where does 5/sqrt29 and 3/sqrt34 come from? Please see the image for reference:

    http://i.imgur.com/4ruELnE.png

    Thank you
     
  2. jcsd
  3. Nov 24, 2014 #2
    Apparently I'm told to use the system of equations to find HG? Or HC? What does this mean, and how?
     
  4. Nov 24, 2014 #3

    SteamKing

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    When you see factors like 5/Sqrt(29) or 3/Sqrt(34) in truss problems, these almost invariably arise from the geometry (or more accurately, the trigonometry) of a truss member.

    In the equation for ΣMC , what is the length of member HG? What is the horizontal component of the force in member HG?
     
  5. Nov 24, 2014 #4
    HGx = HG(5/sqrt(29))? Then times 5 distance to moment C?

    God, I'm so tired, I've been working and trying hard to figure out all day, I'm going to sleep for now
     
  6. Nov 24, 2014 #5

    SteamKing

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    Yep.
     
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