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A question about floating

  1. Feb 22, 2007 #1
    We know that the density of Al is greater than the density of water, yet why can an aluminum boat can float?
  2. jcsd
  3. Feb 22, 2007 #2


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  4. Feb 22, 2007 #3


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    If an Al boat puzzles you an Aircraft carrier must be simply amazing.
  5. Feb 22, 2007 #4


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    An aluminum boat floats, jarod, because it is made mostly of air! (by volume)
  6. Feb 22, 2007 #5


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    when i was in school, i remember these civil engineering departments like to construct, as a demonstration, a concrete "canoe" and paddle that in a lake or river. not the most efficient watercraft, but it floats.
  7. Feb 22, 2007 #6
    Is it what you meant was the overall density of the aluminum boat is less than the density of water?
  8. Feb 22, 2007 #7
    yeah i've heard about making a concrete slab float, very difficult to do, we really had headaches when this problem was given to us...
  9. Feb 22, 2007 #8
    yes actually the overall density of an object is related to center of gravity and composition of the boat, since the boat is not the Al. part only but also the air inside the total volume, this what makes it lighter than water
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