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Homework Help: Pressure and depth problem

  1. Feb 3, 2004 #1
    I would like someone to tell me the steps for working out this problem. Specifically I would like to know the Equations needed to use for the problem.

    Here is the problem. It seems very simple, but I seen to get lost in converting SI Units and then I get confused.

    A Piece of wood is 2cm X 4cm X 2mm. It has a density of 450 kg/m/m. To what Depth will it sink in water?

    Anyhow, I dont know exactly what to do. I found the Volume in Meters but I have no clue if it is correct. So I then found the mass from the Density and Calculated Volume. I plug the Volume in the Bouyant Force Equation, then I find the Force of weight of the object. What do I do next? Do I find the apparent Force and divide it by Volume? I have no Idea how to find the Depth. I would like a good Explanation as well. Thanks.
     
  2. jcsd
  3. Feb 4, 2004 #2
    Is density 450kg/m^3?
    We don't know your object's rotation? On which side is it sinking?
    Since G=F_b
    [tex]
    V_{sunk}d_{fluid}=V_{object}d_{object}
    [/tex]
    As you will see the volume under water is the same no matter its rotation.
     
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