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Homework Help: Gas law problem

  1. Jan 5, 2009 #1
    1. The problem statement, all variables and given/known dataA meteorological baloon had a radius of 1 m when released from sea level and expanded to a radius of 3 m when it had risen to it's maximum altitude, where the temperature was -20.0C. What is the pressure inside the ballon at that altitude?

    2. Relevant equations PV = nRT (I assumed ideal behavior)
    n & R are constant, so
    P1V1/T1 = P2V2/T2

    3. The attempt at a solution
    initial volume= 4/3pi (1m)^3=4.187 m^3
    final temp = 253K
    final volume = 4/3 pi (3)^3=113.04 m^3

    Can I assume STP at sea level and use 1 atm for initial pressure and 273K for initial temperature? Or is there more to it than that?

    If I do that I get .03 atm. This sounds reasonable, but I am not sure the assumtions I made are correct.
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Jan 5, 2009 #2


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    Science Advisor
    Homework Helper

    Your assumptions sound pretty reasonable to me.
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