Understanding the Isothermal Process: Temperature and Internal Energy Explained

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SUMMARY

An isothermal process is characterized by a constant temperature, resulting in zero change in internal energy, which leads to the conclusion that heat (Q) equals work (W). The equation Q = mc(delta T) is not applicable to the system during an isothermal process, as it pertains to the surroundings instead. For an ideal gas, the internal energy remains unchanged despite work being done on or by the system, necessitating heat exchange to maintain temperature. This understanding clarifies the relationship between heat, work, and temperature in thermodynamic systems.

PREREQUISITES
  • Understanding of thermodynamic processes, specifically isothermal processes
  • Familiarity with the ideal gas law and its implications
  • Knowledge of internal energy concepts in thermodynamics
  • Basic principles of heat transfer and work in physical systems
NEXT STEPS
  • Study the first law of thermodynamics and its application to isothermal processes
  • Explore the behavior of ideal gases under various thermodynamic processes
  • Learn about heat transfer mechanisms in different mediums (air, water, etc.)
  • Investigate real-world applications of isothermal processes in engineering systems
USEFUL FOR

Students of thermodynamics, engineers working with heat engines, and anyone interested in the principles of energy transfer in physical systems.

101nancyma
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Urgent!Isothermal process

Hi guys. i have a very short question. In an isothermal process, change is temperature is zero, so change in internal energy is zero, thus Q=W. The part that i am confused is that if Q=mc(deltaT) then should be a change in temperature in the isothermal process?
Thanks a lot
 
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Q = mc(delta T) is not the correct equation in this example for the system. It has already been stated that Q must equal W in an isothermal process.

Think of it this way, if the system is a piston and the piston is drawn up then the system should cool. To keep the system at a constant temperature, the system is heated with the same energy that is extracted through work. Likewise, if the system is compressed then the system will have to expel heat to maintain its temperature.

If the system were in some kind of medium (air, water, etc) then the equation Q=mc(delta T) can be used for the surroundings.

Hope this helps.
 


bucher said:
Q = mc(delta T) is not the correct equation in this example for the system. It has already been stated that Q must equal W in an isothermal process.

Think of it this way, if the system is a piston and the piston is drawn up then the system should cool. To keep the system at a constant temperature, the system is heated with the same energy that is extracted through work. Likewise, if the system is compressed then the system will have to expel heat to maintain its temperature.

If the system were in some kind of medium (air, water, etc) then the equation Q=mc(delta T) can be used for the surroundings.

Hope this helps.

I totally understand now..thanks a lot
 

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