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Homework Help: Pressure and volume at each stage Carnot engine

  1. May 1, 2009 #1


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    A carnot engine uses 0.05kg of air as the working substance. The temperature limits of the cycle are 300K and 940K, the maximum pressure is 8400KPa, and the heat added per cycle is 4.2KJ. Determine the pressure and volume at each state of the cycle.

    r(gamma)=1.4 and R=0.287KJ/Kg K

    im pretty sure the state equations are
    W=m*R*T*ln(v2/v1) for the isothermal expansions and
    T*V^(r-1)=T*v^(r-1) for the adiabatic expansions,

    but I have no idea how to use them, any help would greatley help.
  2. jcsd
  3. May 2, 2009 #2


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    Welcome to Physics Forums :smile:

    Use the information about the maximum temperature and pressure to get P and V at one of the "corner points" in the cycle. This is a good starting point from which you can figure out how things change as one goes around the cycle.
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