mat-sln-asn-hwk29-fa04 - entropy of a closed system cannot...

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Solution for Homework 29 Thermodynamics, Practice Test 7 due Solution to Homework Problem 29.1() Problem: Explain in your own words each of the four Laws of Thermodynamics. Solution See the thermo notes. 1 point(s) (4 times) : Each correctly (or close) stated thermo law. Total Points for Problem: 4 Points Solution to Homework Problem 29.2() Problem: Explain why biological evolutionary theory (and the progressive decrease in entropy that it seemingly implies) does not violate the Second Law of Thermodynamics. Solution In most cases, biological evolution represents a signiFcant increase in the ordering of matter over time; modern complex multicellular organisms represent a more highly-ordered form of matter than the single-celled organisms from which they evolved (for example, the human brain is the most highly-ordered form of matter currently known). This means that, over the last billion years or so, the total entropy of the earth has probably decreased (matter on earth has become “more ordered”). This is in apparent contradiction to the Second Law of Thermodynamics, which states that the total
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Unformatted text preview: entropy of a closed system cannot decrease. The key phrase here is closed system . The earth is hardly a closed system. Huge amounts of energy pour onto the earth continually from the sun. It is this energy (or actually a very miniscule amount of it) that plants convert into high-energy chemical bonds, and these organic molecules are used as food by other organisms, and so on. It is this bound energy that ultimately fuels evolution. The entropy of the sun is increasing over time (the sun becomes less ordered), as nuclear energy is converted to electromagnetic radiation and heat, and this increase in entropy more than makes up for the decrease in entropy taking place on earth. If the solar system is taken as the closed system (a fair approximation), the total entropy is certainly increasing over time, in agreement with thermo II. 1 point(s) : Earth is not a closed system. 1 point(s) : Decent explanation. Total Points for Problem: 2 Points Missing Solution...
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This note was uploaded on 05/04/2008 for the course PHYS 2054 taught by Professor Stewart during the Spring '08 term at Arkansas.

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