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Homework Help: Bouyancy Question

  1. Nov 13, 2009 #1
    1. The problem statement, all variables and given/known data

    Fossilized ichthyosaurus remains enable us to estimate their volume. If we assume that a
    3m^3 icthyosaurus was "wightless" when it swam under water. What was its weight in metric tonnes?

    plugging this into the equation would give me B .. not weight??

    2. Relevant equations

    B=Wdisp. lqd ??

    3. The attempt at a solution

    B=V x density x g
    density= 1000 kg/m^3 (assuming fresh water)
  2. jcsd
  3. Nov 13, 2009 #2


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    A floating object displaces it's own weight in water - how much does 3m^3 of water weigh

    ps. actually the question is asking for the mass of 3m^3 of water

    pps. I would imagine they lived in the sea
  4. Nov 13, 2009 #3
    Soo. 1m^3=1025 kg
    3m^3=1025 x 3=3075kg
    1kg=0.001metric tonns
    3075 x 0.001
    =3.075 metric tonnes

    its really that simple? haha
  5. Nov 13, 2009 #4


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    When a question asks for 'weight' in tons you can be sure that not a great deal of thought went into it

    For bonus marks you could fin the density of seawater in the early Jurassic
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