Thermodynamics- Conservation of energy

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SUMMARY

The discussion centers on the conservation of energy in thermodynamics, specifically how to adapt the general formula for application to Earth. The formula in question is (Qin-Qout) + (Win- Wout) + (Emass,in- Emass,out)= ΔU + ΔKE + ΔPE. A participant suggests simplifying it to (Qin-Qout) + (Win- Wout) = ΔKE + ΔPE. However, it is emphasized that for energy conservation, the total change in energy must equal zero, and the right-hand side of the equation may not accurately represent the energy contributions from different sources.

PREREQUISITES
  • Understanding of thermodynamic principles, specifically conservation of energy.
  • Familiarity with the terms: heat transfer (Q), work (W), and energy changes (ΔU, ΔKE, ΔPE).
  • Knowledge of system boundaries in thermodynamics.
  • Ability to interpret and manipulate thermodynamic equations.
NEXT STEPS
  • Study the implications of the first law of thermodynamics in real-world applications.
  • Explore how to define system boundaries in thermodynamic problems.
  • Learn about energy transfer mechanisms, including heat and work.
  • Investigate the differences between closed and open systems in thermodynamics.
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Students in thermodynamics courses, educators teaching energy conservation principles, and professionals involved in energy management and engineering applications.

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Homework Statement


Hello everyone, I was hoping I could get someone to help me out please. I am having great difficulty with my thermodynamics course and I have an assignment due tomorrow.
I need to reduce the conservation of energy formula so that it applies to Earth so I can work on my assignment.

Homework Equations


(Qin-Qout) + (Win- Wout) + (Emass,in- Emass,out)= ΔU + ΔKE + ΔPE

The Attempt at a Solution


This is the way I think it is
(Qin-Qout) + (Win- Wout) = ΔKE + ΔPE

please let me know if I'm right or if I should add or remove other components
Thank you
 
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We need the context and the specific meanings of the letters to hep you.
Note: for conservation of energy, the total change in energy is zero. If you have anything left over, energy is not conserved.
In thermodynamics, the "system" is usually not closed in this way - energy enters of leaves the (say) gas as heat, work, or with the mass (i.e. as kinetic energy in an escaping gas). So the LHS of your relation looks good. The RHS is a bit of a mystery, it looks to me like you have terms from different models.
These would be internal energy contributions from different sources right?

So it would help to see your reasoning.
 

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