Calculating Internal Energy Change: Path 2 of Carnot Cycle Question

In summary, the problem involves finding the change in internal energy of a gas as it is expanded from initial stage i to final stage f along two different paths on a p-V diagram. Path 1 includes three steps with known work values, while path 2 consists of two steps with unknown work values. Equations for calculating work and heat under isothermal and adiabatic conditions are provided, but the values for specific heat capacities are not given. Further information is needed to solve the problem.
  • #1
Munir M
12
0

Homework Statement


A gas is to be expanded from initial stage i to final stage f along either path 1 or path 2 on a p-V diagram. Path 1 consists of three steps: an isothermal expansion(work is 23J in magnitude), an adiabatic expansion(work is 35J in magnitude), and another isothermal expansion (work is 16J in magnitude). Path 2 consists of two steps: a pressure reduction at constant volume and an expansion at constant pressure. What is the change in the internal energy of the gas along path 2?

Homework Equations


ΔE=Q-W[/B]
W=nRTln(Vf/Vi)
W=∫PdV


The Attempt at a Solution


I added up the values from path 1 to be the work done, assuming that like a hess cycle the work done is same regardless of the path taken. I don't know how to get a value of Q as I don't know which equations out there work with isochoric and isobaric conditions.
 
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  • #2
I found equations for isobaric and isochoric conditions. Q=nCpΔT and Q=nCvΔT. I still don't know how to solve it as none of the values for Cv and Cp are provided.
 

What is the Carnot Cycle?

The Carnot Cycle is a theoretical thermodynamic cycle that describes the most efficient way to convert heat into work. It consists of four reversible processes: isothermal expansion, adiabatic expansion, isothermal compression, and adiabatic compression.

Who created the Carnot Cycle?

The Carnot Cycle was developed by French physicist Sadi Carnot in 1824. He was trying to understand the limitations of steam engines and their efficiency.

What is the purpose of the Carnot Cycle?

The purpose of the Carnot Cycle is to describe the maximum possible efficiency of a heat engine. It serves as a theoretical model for understanding the limitations of real-world heat engines and improving their efficiency.

What are the four processes of the Carnot Cycle?

The four processes of the Carnot Cycle are isothermal expansion, adiabatic expansion, isothermal compression, and adiabatic compression. These processes involve the transfer of heat and work in order to convert thermal energy into mechanical work.

What is the efficiency of the Carnot Cycle?

The efficiency of the Carnot Cycle is given by the formula η = 1 - Tcold/Thot, where Tcold is the temperature of the cold reservoir and Thot is the temperature of the hot reservoir. This means that the efficiency of the Carnot Cycle is dependent on the temperature difference between the two reservoirs, with higher efficiency achieved with a larger temperature difference.

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