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  1. Mar 22, 2008 #1
    Question ...

    i have problem with these 2 questions.i been cracking my head the whole day about this/ anyone please help. please write down the steps for me if possible. thanks a lot in advance.

    1) 0.25 kg of combustion gas in a diesel engine cylinder is at temperature of 727°C. The gas expands at constant pressure until its volume is 1.8 times its original value. For the combustion gas, R = 0.302 kJ/kgK and Cp = 1.09 kJ/kgK. Find the following:
    a) temperature of the gas after expansion
    b) heat transferred
    c) work transferred

    2) A quantity of gas has an initial pressure and volume of 0.1 MN/m2 and 0.1 m3, respectively. It is compressed to a final pressure of 1.4 MN/m2 according to the law pV1'26 = constant. Determine the final volume of the gas.
    Last edited: Mar 22, 2008
  2. jcsd
  3. Mar 22, 2008 #2


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    Staff Emeritus
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    Gold Member

    Hi Junec & welcome to PF,

    What have you attempted thus far?
  4. Mar 22, 2008 #3


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    Homework Helper

    a)If you know it expands at constant pressure....What does that mean for Volume and Temperature? (Check what Charles's law says about it)
    b)What is the definition of [itex]C_p[/itex]?
    c) Do you know a formula for finding the Work done by a gas when it expands its volume at a constant pressure?
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