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Homework Help: What is the different between filled rapidly and filled slowly?

  1. Dec 12, 2004 #1


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    I don't understand this problem. What is the different between filled rapidly and filled slowly? I think in c, when it's filled slowly, the temperature would stay the same at T= 280 K but what's about a and b. How can I do those? Any hint, please. Oh, and here is the problem

    Oxygen gas at T- 280 K and atmospheric pressure is used to fill in an oxygen tank in Cesna 210 aircraft. The oxygen cylinder has a volumn of 11.4 liters and the oxygen pressure when the tank is full is at 122 atmosphere.

    If the tank is filled rapidly, the oxygen is compressed adiabatically. In this case,
    a, how much oxygen fills the tank?
    b, what is the final temperature of oxygen at the instant the tank is filled
    c, If the tank is filled slowly and isothermally, how much oxygen (in kg) is required to fill the tank?

    Thanks a lot!
  2. jcsd
  3. Dec 12, 2004 #2


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    I think the answer to your question is contained in the problem's text,and u seemed to get it.If that tank is filled quickly,then the gas will suffer a general transformation in which it cannot ("it doesn't have time") change het with the environment.When it's filled slowly,then it is always in thermal equilibrium with the surroundings,and to do that,it changes heat constantly with the surroundings,and the trabsformation is an isothermal one.
    As for the problem itself,with these having been made clear,u can assume for the points a) and b) that the transformation is adiabatica/isentropical and apply the formula for a general transformation of this kind.Don' forget that the adiabatical exponent "\gamma" is calculated for a diatomical molecule and it is found to be 7/5.
    For the point c),thing are simpler,because the law of transforlation gets the simple form:pV=const.

    Good luck!!
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