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Homework Help: Rate of oxygen consumption while sleeping

  1. Oct 9, 2012 #1
    1. The problem statement, all variables and given/known data The oxygen taken in by the body reacts with fats, carbohydrates, and protein, liberating energy internally at a rate of about 2.180×104 J/L. If a 71.40 kg man requires 81.00 W of power even while sleeping, what is his rate of oxygen consumption?

    2. Relevant equations p=fv
    f=mg


    3. The attempt at a solution i found a value for v but iam not sure how the internal energy plays into the answer??? the value i got for v is wrong so iam not sure if i did the problem wrong or if it has to do with the other rate?
     
  2. jcsd
  3. Oct 9, 2012 #2

    Borek

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    Staff: Mentor

    Show what you did and how yo got the (incorrect) value. It is not clear to me what should be the unit of your answer - L/min? mL/sec? Something else? These can be easily interconverted though.

    81 W - how many J per second? How many liter of oxygen per this number of J?
     
  4. Oct 9, 2012 #3
    i divided the power by force(mg) to find v but i see that i would need to cancel the jouls out. my answer can be in mL/sec....
     
  5. Oct 9, 2012 #4

    AGNuke

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    Gold Member

    Is the answer is approximately 3.72 mL/sec?
     
  6. Oct 10, 2012 #5

    Borek

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    Staff: Mentor

    That's off.

    OK. Follow the reasoning from my previous post - have you at least tried to understand it?
     
  7. Oct 10, 2012 #6
    oh i see the watt is equal to J/s and the initial rate in J/ml is 21.8 so i just divide to get ml/s. thanks
     
  8. Jan 2, 2013 #7
    @Nuke done, i think you're right
     
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