Maximum work Definition and 22 Threads

I am continuing to try to understand maximum work reversible processes (and a subset thereof -- Carnot cycles) better. I am here curious about the following system. My question is about how I can know/prove that there exists a way to take the gas (the primary subsystem) reversibly with respect...

I am reading Landau's Vol 5 on Statistical Physics and have trouble grasping some concepts in Section 20. If I understand this correctly, the body and the medium are in direct contact and can exchange work and heat while the object can only exchange work with the body. So the minimum...

Hi, I have been studying thermodynamics from Herbert Callen's "Thermodynamics : an introduction to the physical theories of equilibrium thermostatics and irreversible thermodynamics" In Chapter 4, Section 4.4, he writes : " all processes occurring between a given initial and a given final state...

Homework Statement Homework EquationsThe Attempt at a SolutionTaking the engine to be a Carnot engine, ## \eta = \frac { T_h – T_c } {T_h} = \frac { W} {Q_h} ## ...(1) ## Q_h = C(T_h – T_f) ...(2) \\ Q_c = C(T_f – T_c) ...(3) \\ W = Q_h – Q_c = C(T_h + T_c – 2 T_f) ## ...(4)Solving...

Homework Statement A CD case slides along a floor in the positive direction of an x-axis while an applied force Fa acts on the case. The force is directed along the x-axis and has the x component Fax = 7.0x – 2.0x^2, with x in meters and Fax in Newtons. The case starts at rest at the position x...

Homework Statement Assume that one mole of an ideal van der Waals fluid is expanded isothermally, at temperature T_h from an initial volume V_i to a final volume V_f. A thermal reselvoir at temperature T_c is available. Apply dW_{RWS} = \left ( 1 - \frac{T_{RHS}}{T} \right ) (-dQ) +(-dW) to a...

Given that in a Carnot Cycle the two adiabatic processes are essentially equal and opposite in magnitude the total work done by the cycle is in the two isotherms. The total work of the system is generally given as -NR(Th-Tc)ln(Vb/Va). Does this mean that the work done by a monatomic ideal gas is...

Homework Statement 2 boxes containing the same number of moles of 2 ideal identical gases with the same adiabatic index (this is given as gamma), at the same initial temperature Ti but with different volumes, V1 and V2 are brought together. Find the maximum mechanical work that can be obtained...

Hi everyone : I have a question: how to calculate the maximum work delivered by a turbine. Steam input T and pressure are given plus the outlet pressure only. Using Peng-Robinson equation of state. Adiabatic process. I tried to find outlet temperature by trial and error using Peng-Robinson EOS...

Hello, The Gibbs free energy is the maximum amount of non-expansion work that can be extracted from a closed system; this maximum can be attained only in a completely reversible process. This maximum work is equal to H-TS. My question is this TS energy is what kind of energy? and from where it...

What does it mean by maximum work of an isothermal, reversible expansion of a perfect gas from initial volume Vi to final volume Vf at temperature T? I understand that heat enters the system during this expansion to ensure that no internal energy is lost but it doesn't really help in anyway...

My book says 'Maximum work can be obtained only from thermodynamically reversible processes,' but why is it so? What is the cause? Actually to me the definition of reversible process is confusing. It says that at each step during the process, equilibrium is maintained. But, let's say,we have to...

Homework Statement I am trying to understand the implications of the principle that the maximum non-expansion work, dwadd is equal to the Gibbs energy change for a reversible process. Homework Equations For a reversible process, dwadd = dG. This is provided that the process takes...

Homework Statement Each of three identical bodies has an equation of state U=NCT, with NC=2 cal/K. Their initial temperatures are 200 K, 250 K and 540 K. What is the maximum amount of work that can be extracted in a process in which these three bodies are brought to a final common temperature...

Two idential, finite sized bodies of constant volume and constant heat capacity are used to drive a heat engine- heat is taken from the hot (Th) body, work is done, and heat is ejected to the cold (Tc) body. Both bodies wind up at Tf (a) What is the change in the entropy of the system? (b)...

Homework Statement One mole of a liquid with a constant molar heat capacity of 132 j/mol K is initially at a temp of 80 C. The heat capacity is independent of tempearture. Calculate the maximum work that could have been done onthe surroundings while cooling the liquid reversibly. The...

My Question - Steam at 200 psi and 600 F flows through a turbine operating adiabatically and exits at atmospheric pressure. For every kilogram of steam flowing through the turbine there are 150 Btu of shaft work delivered. (a) What is the final condition of the exit steam? (b) What is the...

Homework Statement A 200 litre container of boiling water and a 200 litre container of ice cold water are used as heat source and sink for a Carnot engine. Calculate the maximum amount of useful work that can be obtained from the system and the final temperature of the two containers of...

Homework Statement An object maintained at constant volume has heat capacity Cv, which is independent of T. The object is initially at a temperature Th, and a heat reservior at a lower temperature Tc is available. Show that the maximum work that can be extracted when a heat engine operating...

maximum work during reversible process? I have seen maximum work is achievable when the process is carried out reversibly. Is it correct? For example, if you look at the following problems, 1) Ten litres of an ideal gas at a pressure of 10 atm expands isothermally against a constant...

Maximum work function?? Homework Statement What is the maximum work function for a surface to emit electrons when illuminated with 900nm infrared light? Homework Equations K= 1/2mv2 = hf - work function wavelength =h/p = h/mv The Attempt at a Solution p=h/wavelength =...

How would you guys explain "qualitatively" the theorem of maximum work based on this diagram. (that is when a process is reversible and no entropy change in the universe) I don't really know what the graph means. Let's say it's an ideal gas, (S=LnU+...). The diagram divides the plane in two...