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Homework Help: The Bends- Volume change

  1. Dec 3, 2012 #1
    1. The problem statement, all variables and given/known data
    If deep-sea divers rise to the surface too quickly, nitrogen bubbles in their blood can expand and prove fatal. This phenomenon is known as the bends. If a scuba diver rises quickly from a depth of 23m in Lake Michigan (which is fresh water), what will be the volume at the surface of an N2 bubble that occupied 1.0 mm3 in his blood at the lower depth?(Assume that the pressure difference is due only to the changing water pressure, not to any temperature difference, an assumption that is reasonable, since we are warm-blooded creatures.)
    V= mm3

    2. Relevant equations
    density of water= 1000 kg/m3

    3. The attempt at a solution
    First, I found the pressure at 23m to be 3.23 atm
    Then, I assumed that at the surface the pressure would be 1atm.
    Finally using the pv=pv equation i found the V= 3.2mm3. However, this was incorrect. Am I doing this completely wrong?
    Last edited: Dec 3, 2012
  2. jcsd
  3. Dec 3, 2012 #2
    I got the same answer as you. Who says 3.22 mm3 is incorrect? Check and see whether surface tension effect should be included.
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