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    Heat Transfer clarification of a problem

    Homework Statement We're currently studying steady state one dimensional conduction heat transfer. We've touched on some surface convection, resistances in layers and fins. I don't think I'll have much issue with this problem once I find this out: What is a thermal driving force?
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    Thermodynamics: Piston-Cylinder

    Just as a heads up, the finished integral for work for a polytropic process turns out to be pretty simple. for p(v^n)=c P=pressure v=specific volume W/m=(P2v2-P1v1)/(1-n)
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    Thermodynamics: Control Volume analysis using energy

    You know what, based on the information given, I would let velocity drop out as well. In a basic thermo class most prevalent place you're going to see velocity -not- being negligible is in nozzle and diffuser problems, or where it is expressively given to you in the problem statement.
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    Thermodynamics: Control Volume analysis using energy

    I would treat this as a steady state problem. Meaning your mass flow rate in is going to equal your mass flow rate out. and de/dt is zero. Since we're not given any sorts of elevation, the potential energy will be drop out. No work is happening, so W will also drop out. You will be...
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    Heat exchanger calculation

    Well, if you look at it from a first law perspective for one of the streams. Q=m(h(out)-h(in)) If you decrease m, regardless of the factors of h, Q will decrease.
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    I need Help with Thermodynamics

    Closed system, control mass. What you're going to want to do is model both objects as incompressible. ca=specific heat aluminum ci=specific heat iron m=mass Tf=temp final Ti=temp Fe Ta=temp Al Imcompressible 1st Law U=Q-W Q=0, W=0 U=0 U=m*c*(T2-T1) so Ui+Ua=0 then...