chapter 24 thermodynamics. absolute zero absolute zero is a theoretical temperature at which atoms...
TRANSCRIPT
![Page 1: Chapter 24 Thermodynamics. Absolute Zero Absolute zero is a theoretical temperature at which atoms that make up matter have zero kinetic energy. They](https://reader035.vdocuments.net/reader035/viewer/2022062217/56649ec95503460f94bd60f2/html5/thumbnails/1.jpg)
Chapter 24Thermodynamics
![Page 2: Chapter 24 Thermodynamics. Absolute Zero Absolute zero is a theoretical temperature at which atoms that make up matter have zero kinetic energy. They](https://reader035.vdocuments.net/reader035/viewer/2022062217/56649ec95503460f94bd60f2/html5/thumbnails/2.jpg)
Absolute Zero
Absolute zero is a theoretical temperature at which atoms that make up matter have zero kinetic energy. They are at rest.
Watch the NOVA program “Absolute Zero” on Youtube.
Keywords “Absolute Zero”
![Page 3: Chapter 24 Thermodynamics. Absolute Zero Absolute zero is a theoretical temperature at which atoms that make up matter have zero kinetic energy. They](https://reader035.vdocuments.net/reader035/viewer/2022062217/56649ec95503460f94bd60f2/html5/thumbnails/3.jpg)
First Law of Thermodynamics
• Heat that is added to a system can be converted to equal amounts of some other form of energy.
• Another way to state the first law of thermodynamics is:
Energy cannot be created or destroyed but can be transformed from one form to another in a thermal system
• The first law of thermodynamics is simply the law of conservation of energy applied to thermal systems
![Page 4: Chapter 24 Thermodynamics. Absolute Zero Absolute zero is a theoretical temperature at which atoms that make up matter have zero kinetic energy. They](https://reader035.vdocuments.net/reader035/viewer/2022062217/56649ec95503460f94bd60f2/html5/thumbnails/4.jpg)
Adiabatic Processes
The process of compression or expansion of a gas so that no heat enters or leaves a system is said to be adiabatic.
![Page 5: Chapter 24 Thermodynamics. Absolute Zero Absolute zero is a theoretical temperature at which atoms that make up matter have zero kinetic energy. They](https://reader035.vdocuments.net/reader035/viewer/2022062217/56649ec95503460f94bd60f2/html5/thumbnails/5.jpg)
change in air temperature ~ pressure change
As air pressure decreases with altitude, so does the temperature. Air temperature decreases by about 5 °F for every 1000 feet of elevation.
Since cold air holds less water vapor than warm air, the relative humidity gradually increases until it is saturated:
100% relative humidity
The temperature at which the air is saturated is called the dew point.
![Page 6: Chapter 24 Thermodynamics. Absolute Zero Absolute zero is a theoretical temperature at which atoms that make up matter have zero kinetic energy. They](https://reader035.vdocuments.net/reader035/viewer/2022062217/56649ec95503460f94bd60f2/html5/thumbnails/6.jpg)
change in air temperature ~ pressure changechange in air temperature ~ pressure change
Adiabatic cooling of the air that results in the formation of clouds often occurs around mountains (orographic lifting).
![Page 7: Chapter 24 Thermodynamics. Absolute Zero Absolute zero is a theoretical temperature at which atoms that make up matter have zero kinetic energy. They](https://reader035.vdocuments.net/reader035/viewer/2022062217/56649ec95503460f94bd60f2/html5/thumbnails/7.jpg)
Adiabatic cooling of the air results in a “Rain Shadow” effect:
![Page 8: Chapter 24 Thermodynamics. Absolute Zero Absolute zero is a theoretical temperature at which atoms that make up matter have zero kinetic energy. They](https://reader035.vdocuments.net/reader035/viewer/2022062217/56649ec95503460f94bd60f2/html5/thumbnails/8.jpg)
Where are the driest places on earth?
• Atacama Desert:
![Page 9: Chapter 24 Thermodynamics. Absolute Zero Absolute zero is a theoretical temperature at which atoms that make up matter have zero kinetic energy. They](https://reader035.vdocuments.net/reader035/viewer/2022062217/56649ec95503460f94bd60f2/html5/thumbnails/9.jpg)
Second Law of Thermodynamics
• Heat flows from HOT to COLD
![Page 10: Chapter 24 Thermodynamics. Absolute Zero Absolute zero is a theoretical temperature at which atoms that make up matter have zero kinetic energy. They](https://reader035.vdocuments.net/reader035/viewer/2022062217/56649ec95503460f94bd60f2/html5/thumbnails/10.jpg)
Efficiency of a Heat Engine
• Carnot Efficiency: The efficiency of a heat engine depends on the temperature difference between the hot reservoir and the cold sink.
Ideal Efficiency = Thot – Tcold
Thot
![Page 11: Chapter 24 Thermodynamics. Absolute Zero Absolute zero is a theoretical temperature at which atoms that make up matter have zero kinetic energy. They](https://reader035.vdocuments.net/reader035/viewer/2022062217/56649ec95503460f94bd60f2/html5/thumbnails/11.jpg)
Entropy
• Natural systems tend to proceed toward a state of greater disorder
• Entropy - is the measure of the amount of disorder in a system.
• Whenever a physical system is allowed to distribute its energy freely, it always does so in a manner such that entropy increases while the available energy of the system for doing work decreases.
![Page 12: Chapter 24 Thermodynamics. Absolute Zero Absolute zero is a theoretical temperature at which atoms that make up matter have zero kinetic energy. They](https://reader035.vdocuments.net/reader035/viewer/2022062217/56649ec95503460f94bd60f2/html5/thumbnails/12.jpg)
Summary:
First Law of Thermodynamics:
Energy cannot be created or destroyed, but can be transformed to other forms within a thermal system
Second Law of Thermodynamics
Entropy: Natural systems tend to proceed to a state of greater disorder