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Homework Help: Energy Transfer

  1. Apr 6, 2008 #1
    A 5 kg of steam contained within a piston-cylinder assembly undergoes an
    expansion from state1, where the specific internal energy is u1 2709.9 kJ/kg,to state 2, where u2 2659.6 kJ/kg. During the process, thereis heat transfer to the steam with a magnitude of 80 kJ. Also, a paddle wheel transfers energy to the steam by work in theamount of 18.5 kJ. There is no significant change in the kinetic or potential energy of the steam. Determine the energytransfer by work from the
    steam to the piston duringthe process, in kJ.

    Anybody have an idea as to how this can be answered?
  2. jcsd
  3. Apr 6, 2008 #2


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    Please read the forum Guidelines. We can not help with textbook problems unless you show some effort first. Also, next time round, use the Homework & Coursework Forum near the top of the main page.
  4. Apr 6, 2008 #3

    u = uf + x(ug-uf) Q= u2-u1

    Should i use this equation or which one?
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