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Homework Help: Weight of copper hanging/submerged

  1. Mar 24, 2009 #1
    A scale reads 220N when a piece of copper is hanging from it. What does the scale read when it is lowered so the copper is submerged in fresh water.

    From a given chart

    copper is 8930 kg/m^3
    fresh water is 1000kg/m^3

    I found my volume of copper to be .0025m^3

    I'm just not sure which direction to go now?
    Last edited: Mar 24, 2009
  2. jcsd
  3. Mar 24, 2009 #2


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    Gold Member

    What forces are involved in buoyancy? Draw a free body diagram. Also write down the definition of buoyancy? Does anything click?
  4. Mar 24, 2009 #3


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    Since when was volume measured in Kg?
  5. Mar 24, 2009 #4
    The forces involved are those from bottom and those on top of object. I have drawn the diagram and I think I know the connection I'm trying to make. The volume of the displaced fluid times density has to relate to the buoyant force? I think its the Newtons thats throwing me off
  6. Mar 24, 2009 #5
    indeed my teach would've smacked me
  7. Mar 24, 2009 #6
    geezzzz nevermind I got it. I thought i was looking over something simple.

    While obtaining the forces I was neglecting my 9.8m/s^2
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