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Homework Help: Steel bridge - increase dimensions by 5

  1. Nov 5, 2004 #1
    If you increase the dimensions of a bridge by 5, how much is its strength increases? How much is its weight increased?
    Any help is appreciated.
  2. jcsd
  3. Nov 6, 2004 #2

    Doc Al

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    Staff: Mentor

    Assume that the components of the bridge can withstand a certain amount of stress: Force per unit area. Thus the "strength" of the bridge (maximum force the bridge components can support) is proportional to the cross-sectional area.

    If all dimensions of the bridge are multiplied by 5, what happens to the cross-sectional area of each component? And what happens to the volume, and thus the weight?
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