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Homework Help: Triple beam balance

  1. Aug 26, 2010 #1
    1. The problem statement, all variables and given/known data
    what is the measurement
    110.jpg


    2. Relevant equations



    3. The attempt at a solution
    Is there something wrong with the picture or is it possible to have beam balance with two same scales (the upper and middle ones). If possible then the reading = 90 + 30 + 8 = 128 g ??

    Thank you very much
     
  2. jcsd
  3. Aug 26, 2010 #2
    Sure, why not? Okay, I'll admit that I don't know exactly how beam balances work, but if it works as different torques correlated to forces then all its doing is summing torques and then telling you how those torques would relate to mass.
     
  4. Aug 27, 2010 #3
    I don't fully understand what you mean. The pointer just shows the mass of the object when the beam is balanced. If it is possible to have a beam balance like that, then I guess I got the correct answer?

    Thank you very much
     
  5. Aug 27, 2010 #4
    Sorry, but I don't fully understand what you mean. Why do you think it is not possible?
     
  6. Aug 27, 2010 #5
    because I think one of the scales (upper or lower one) should be in hundreds. I never encountered a problem which had the same scales and I also think that it is not very useful if the beam balance has two same scales because it can not be used to measure an object which mass is in several hundreds term (maybe around 300 gram above)
     
  7. Aug 27, 2010 #6
    It all depends on the context. I think that the ones not being completely accounted for is the stranger part than having 30-50 and 50-100. It's a possible scale, and without context who knows why it is configured in this manner.
     
  8. Aug 27, 2010 #7
    OK, I am just afraid that the scales have different meaning, such as the middle must be multiply by 10, so the reading should be 300 instead of 30. But maybe I am just overthinking about it.

    Thank you very much
     
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