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Homework Help: How to weigh an object that's heavier than the max. weight of the spring scale

  1. Nov 23, 2007 #1
    1. The problem statement, all variables and given/known data
    suppose that a spring is used in a spring scale that is limited to a maximum value of 25N, but you would like to weigh an object of mass M that weighs more than 25N.
    What commonly available equipment, along with the spring scale, can be used to determine the weight of the object without breaking the scale?

    3. The attempt at a solution
    I have a feeling that attaching another spring to the scale would work, but I don't know how to explain why, and how i would then determine the weight of the >25N object.

    Any suggestions?
  2. jcsd
  3. Nov 23, 2007 #2


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    Science Advisor
    Homework Helper

    Depends how you were planing to attach the other scale.
    Forget scales for a moment and imagine you had a rope with a breaking strain of 1Ton and you needed to lift 1.5T, does it become obvious how to attach two ropes? How much force would be on each rope ?
    How does this translate to the scales?

    Another approach would be to build a balance with another 25N weight - then arrannge it so the scale only measures the difference. This is actually how high precision balances work.
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