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Homework Help: Carnot Heat Engine

  1. Nov 9, 2011 #1
    1. The problem statement, all variables and given/known data

    Consider a Carnot engine that operates between a hot reservoir at 63°C and a cold reservoir at -14°C. In running 25 minutes, this engine absorbs 590 J of heat from the hot reservoir.

    How much heat does it expel to the cold reservoir?

    2. Relevant equations
    [tex]Q_H/Q_C = T_H/T_C[/tex]
    3. The attempt at a solution
    [tex]T_H = 336k[/tex]
    [tex]T_C = 287k[/tex]
    [tex]Q_H/Q_C = T_H/T_C \longrightarrow 590/Q_C = 336/287[/tex]
    Solving for [tex]Q_C[/tex] I get 504 J, however, this is not the correct answer. What am I missing?
  2. jcsd
  3. Nov 10, 2011 #2
    Are you sure Tc= 287 K? The cold reservoir is at -14 C
  4. Nov 10, 2011 #3
    Wow. It happened that on the site my homework is on, the negative sign and the number were on different lines, so I totally missed it. Thank you very much.
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