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Homework Help: Specific gravity in water

  1. Dec 17, 2006 #1
    1. The problem statement, all variables and given/known data

    A sample of an unkown material weighs 200 N in air and 150 N when immersed in water. What is the specific gravity of this material?

    2. Relevant equations
    specific gravity = (density/density of water)
    density of water is 1000 kg/m^3


    3. The attempt at a solution

    I don't even know where to start. All my text book says is the specific gravity of a substance is the ratio of its density to the density of the water at 4 degrees C. I don't know how to relate this to an equation or begin to solve it.
     
  2. jcsd
  3. Dec 17, 2006 #2

    AlephZero

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    Hint: use Archimedes' Principle (or the Law of Buoyancy - a different name for the same thing)
     
  4. Dec 17, 2006 #3

    ShawnD

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  5. Dec 17, 2006 #4
    Thanks alot guys, it makes alot more sense now.
     
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