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Homework Help: Relative weights in air and water

  1. Apr 22, 2015 #1
    1. The problem statement, all variables and given/known data
    Two solid pieces, one of steel and the other of aluminium when completely immersed in water have equal weights. When these solid pieces are weighed in air, aluminium seems to weigh more. Why is this so? On what factors in this being decided?

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Apr 22, 2015 #2


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    You need to show an attempt at a solution.

    What do you know? Where are you stuck?
  4. Apr 27, 2015 #3
    The relevant principle , I think , is the Archimedes' Principle.
    According to it, weight in air-weight in liquid=Upthrust experienced.
    Weight in liquid is the same for both, There is no information about volume or upthrust experienced of the solids.
    So, I'm pretty much stuck too....
  5. Apr 27, 2015 #4


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    There is some information in the given
    which -- when properly dealt with in your relevant equation -- can help you further.
  6. Apr 27, 2015 #5


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    It might help if you create symbols for the unknown densities and volumes of the two objects. You can then express the facts you are given as equations and inequalities and see what you can deduce.
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