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Homework Help: Pv concept stuck on this one

  1. Sep 24, 2011 #1
    A gas expands according to the equation pv=1000. where p is pressure in kPa and v is specific volume m^3/kg. If the gas pressure drops from 1000 to 500kPa, how much work was done by the gas??

    Ok I am new to thermo and given a question and can't figure it out.
    Do I use net flow work = p2v2-p1v1??
    Answer is 693.1 kJ/kg.

    or is it w-p delta v?
    I am not sure.
    Any help or direction would help thanks
  2. jcsd
  3. Sep 24, 2011 #2
    Start from
    work = force x displacement
    BUT remember that the force is not constant.
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