Calculating Entropy Change in Niagara Falls Waterfall

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SUMMARY

The discussion focuses on calculating the increase in entropy per second for water falling at Niagara Falls, specifically 5.0 x 10^3 m³ of water falling 50.0 m. The temperature of the water and surroundings is assumed to be constant at 20.0°C. The key formula used is S = ∫ dQ/T, where the potential energy converts to kinetic energy and subsequently to heat energy, allowing for the calculation of entropy change. The final solution involves determining the heat transfer (Q) and dividing it by the constant temperature (T).

PREREQUISITES
  • Understanding of thermodynamics principles, specifically entropy
  • Familiarity with the concept of potential and kinetic energy
  • Knowledge of the formula S = ∫ dQ/T for entropy calculation
  • Basic calculus for integrating heat transfer over time
NEXT STEPS
  • Study the laws of thermodynamics, focusing on entropy and heat transfer
  • Learn about potential and kinetic energy transformations in fluid dynamics
  • Explore advanced entropy calculations in different thermodynamic processes
  • Investigate real-world applications of entropy in engineering and environmental science
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Students studying thermodynamics, physics enthusiasts, and professionals in engineering fields who require a solid understanding of entropy changes in dynamic systems.

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Homework Statement


Every second at Niagara Falls, some 5.0 10^3 m3 of water falls a distance of 50.0 m. What is the increase in entropy per second due to the falling water? Assume that the mass of the surroundings is so great that its temperature and that of the water stay nearly constant at 20.0°C. Also assume a negligible amount of water evaporates.

Homework Equations



S = ∫ dQ/T

The Attempt at a Solution



Well, if I divided across by Δt, then I would have an equation set up for the quantity I need.

Temperature is constant, but since there is no real change in temperature or phase, is there any real change in heat? I'm not sure of where to go from here.

EDIT: Nevermind, I figured it out. Potential Energy converts to Kinetic Energy then to Heat Energy. Entropy is Q/T.
 
Last edited:
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so how do you solve this problem?
 

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