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Homework Help: Ideal Gas Law Problem (Please help )

  1. Jan 26, 2012 #1
    Ideal Gas Law Problem (Please help!!)

    Show that if the temperature in the atmosphere is independent of altitude, then the pressure as a function of altitude y is

    p=(p initial)e^(-mgt/kT)

    Where m is the average mass per molecule of air.

    I really have no idea where to start. Please help!!!! Thank you so much!!!

    I thought maybe you use the ideal gas law and manipulate the variables to get it to match. I tried, but I couldn't get anywhere. Thanks
     
  2. jcsd
  3. Jan 26, 2012 #2
    Re: Ideal Gas Law Problem (Please help!!)

    Try deriving a differential equation for P by using the ideal gas law and calculating the pressure from above and below for a slither of air

    Also in the function you gave p is constant as a function of y (fix this and try using h instead of y this might trigger something)
     
  4. Jan 26, 2012 #3
    Re: Ideal Gas Law Problem (Please help!!)

    Thank you for your response, but I still can't figure out what to do. Find the rate of change of pressure with respect to h, right? doesn't that wind up as a constant if I'm using p=p+gy? That probably makes no sense lol, but I thought I'd show that I attempted to figure it out. I would really appreciate some more help and/or directly what I need to do to get started please!!!
     
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