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Homework Help: Find the heat that flows into or out of the system

  1. Nov 30, 2007 #1
    1. The problem statement, all variables and given/known data
    A system expands by 0.75 m^3 at a constant pressure of 125 kPa. Find the heat that flows into or out of the system if its internal energy
    a. Increases by 65J
    b. Decreases by 1850 J
    give answer kJ

    2. Relevant equations

    3. The attempt at a solution
    P=125 kPA
    delta U=Q-W
    W=P(delta U)
    so i plug in the numbers

    Part a)
    delta U=65kPA

    Q= 158.75 J= .15878 kJ

    Part B)
    1850= Q-93.75
    Q= 1756.25J=1.77kJ

    And the answer is wrong, can someone help me please
  2. jcsd
  3. Nov 30, 2007 #2


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  4. Nov 30, 2007 #3
    no i meant W=P(delta V)
    I just typed in the wrong thing
    sorry for the mistake
    so do you know what i should do
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