A piston-cylinder machine contains 1 kg of air, initially at v = 0.8 m3/kg and 290 K. The gas is compressed in a slow frictionless process to a specific volume of v = 0.2 m3/kg and a temperature of 580 K, according to the equation pv1.5 = 0.75 (where p is in bar and v as shown). Determine the work and the heat transfer.

enter image description here The correct answer for the work from the textbook is -167.72 kJ

Does anyone know why my answer is a factor of 100 too small?

  • 2
    $\begingroup$ What about temperature? $\endgroup$
    – Solar Mike
    Commented Jan 30, 2022 at 19:46
  • 2
    $\begingroup$ You calculate units by actually writing down the units. For instance what units are you using on volume? You haven't tried this. Also, the title is very generic. It would be better to have it better reflect the question. $\endgroup$
    – Eric S
    Commented Jan 30, 2022 at 19:52
  • $\begingroup$ Pay attention to Solar Mike's comment, nowhere in your equation has related the volume change with respect to the temperature change. Also, the integration of P*dv and the subsequent numerical evaluation seems incorrect. $\endgroup$
    – r13
    Commented Jan 30, 2022 at 21:38


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