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Thermodynamics [IdealGases,W,Q, etc.] Much Help Needed-Detailed questions in descrip.

  1. Jan 10, 2013 #1
    I'm sorry I cannot conform to the default format Physicsforums.com; it is because I do not even know the first step to solving these sorts of problems, I don't know which equations to use which is a major problem. Here are the types of questions I require understanding.
    -
    An ideal gas goes through three processes (A>B>C>[A]) (Triangular form) (PV Chart)
    How would I figure out The Q, W, and ΔU (internal energy) for A to B, B to C, C to A?
    -
    On another graph using variables but this time with numerical values for P and V on the axis, how would I find the work done by a monatomic ideal gas as it expands from point A to point C along the path shown in the figure? Also, how much heat would be absorbed BY the gas during this process?
    -
    Finding the net work, heat, and ΔU in another PV Graph with data on the axis-es?
    -
    Calculating temperature, work, and/or internal energy in another PV Graph?
    -
    Whether or not W, Q, or ΔU is positive(gained) or negative(released) in an ideal gas system as well as how those three (Q,W,..U) are related?
    -

    I really wish to work on the problems myself, so I have only asked what procedures I should take.
    Here is a list of equations I have scavenged.

    ΔU = Won + Q

    ΔU = (3/2)nRΔT

    Won = -PΔV

    P1V1 = P2V2

    (P1V1)/T2 = (P2V2)/T2

    PV = nRT

    Is there any important equation that I am missing?
     
    Last edited: Jan 10, 2013
  2. jcsd
  3. Jan 12, 2013 #2
    Re: Thermodynamics [IdealGases,W,Q, etc.] Much Help Needed-Detailed questions in desc

    I think that since you are working with idel gasses, you can dervie most of the stuff from 3-4 equations, namely:
    The ideal gas law : pV = nRT
    The Laws of thermodynamics.(2-3 laws is useful).

    If you want to find the Work done during a isothermal(T constant) step e.g.:
    [itex] W = -\int\limits_{V_1}^{V_2}\! p\,\text{d}V = -\int\limits_{V_1}^{V_2}\! \dfrac{nRT}{V}\,\text{d}V = -nRT\left(\ln(V_2)-\ln(V_1)\right) = -nRT\ln\left(\dfrac{V_2}{V_1}\right)[/itex]
    I hope that I understood your question.
     
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