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Homework Help: Make a bridge out of popsicle sticks homework

  1. Feb 26, 2006 #1
    Hey all,

    I've got a project that I have to do. I have to make a bridge out of popsicle sticks. However, it's a competition and only the winner receives full credit. The bridge with the highest ratio of weight held to bridge weight wins.

    Weight Held (Pounds)
    ------------------------- = Bridge Ratio
    Weight of Bridge (Grams)

    Here are the specs:

    Road Deck
    ---Thickness: Max 1"
    ---Length: 14"<X<18"
    ---Width: Max 6"

    Substructure (Optional)
    ---Depth: Max 3"
    ---Length: Max 14"
    ---Width: Max 6"

    Superstructure (Optional)
    ---Height: No Max
    ---Length: Max 18"
    ---Width: Max 6"

    There will be a whole in the center 3/8" to 1/2". The bridge will be threaded onto a rod followed by a small piece of wood (To even out the pressure a bit) and then a bolt.

    | | | | | | | | | | | | | | | | | | | | | | Bridge

    -------................| |............-------
    \......./................| |.Rod.......\....../
    .|.....|.................| |.............|.....|
    .|.....|.Supports....| |.............|.....|

    Any ideas, suggestions, advice, or help is appreciated.

  2. jcsd
  3. Feb 27, 2006 #2
    A buddy of mine won one of these things (except with balsa wood) in his statics class. He attributed his win to two factors:

    a) He designed the whole bridge in CAD.
    b) He used Gorilla Glue as the adhesive.
  4. Feb 27, 2006 #3
    Oh, sorry, I guess I forgot to post it.

    Posicle Sticks: No Max
    White/Wood Glue

    Also 2 of the large flat surfaces of popsicle sticks may not be glued together.

    Thanks for trying at least.

  5. Feb 27, 2006 #4
    One thing to remember is that the distance between the top chord and bottom chord of a truss type bridge needs to be maxed out in the middle. So, if you are only going to use a road deck for the structure, you only get 1" of separation. I would look at some sort of bow truss and be sure that the deck distrubutes the point lode along the entire truss.
  6. Feb 27, 2006 #5
    Also, build the bridge to the minimum span. It appears that there is a maximum and minimum length. Find out the exact rules.
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