thermodynamics and its implication | Lecture notes Physics

Thermodynamics and its Implication

The laws of thermodynamics define physical quantities, such as temperature, energy,

and entropy, that characterize thermodynamic systems at thermodynamic equilibrium. The laws

describe the relationships between these quantities, and form a basis of precluding the possibility

of certain phenomena, such as perpetual motion. In addition to their use in thermodynamics, they

are important fundamental laws of physics in general, and are applicable in other

natural sciences.

Thermodynamics has traditionally recognized three fundamental laws, simply named by an

ordinal identification, the first law, the second law, and the third law. In addition, after the first

three laws were established, it was recognized that another law, more fundamental to all three,

could be stated, which was named the Zeroth law.

The zeroth law of thermodynamics defines thermal equilibrium and forms a basis for the

definition of temperature: if two systems are each in thermal equilibrium with a third system,

they are in thermal equilibrium with each other.

The first law of thermodynamics: when energy passes into or out of a system (as work, as heat,

or with matter), the system's internal energy changes in accord with the law of conservation of

energy. Equivalently, perpetual motion machines of the first kind (machines that produce work

with no energy input) are impossible.

The second law of thermodynamics: in a natural thermodynamic process, the sum of the

entropies of the interacting thermodynamic systems increases. Equivalently, perpetual motion

machines of the second kind (machines that spontaneously convert thermal energy into

mechanical work) are impossible.

The third law of thermodynamics: the entropy of a system approaches a constant value as the

temperature approaches absolute zero. With the exception of non-crystalline solids (glasses) the

entropy of a system at absolute zero is typically close to zero.

Additional laws have been suggested, but none of them achieved the generality of the four

accepted laws, and are not discussed in standard textbooks.

Law of conservation of energy

In physics and chemistry, the law of conservation of energy states that the total energy of

an isolated system remains constant; it is said to be conserved over time.[1] This law first

proposed and tested by émilie du châtelet, means that energy can neither be created nor

destroyed; rather, it can only be transformed or transferred from one form to another. For

instance, chemical energy is converted to kinetic energy when a stick of dynamite explodes. If

one adds up all forms of energy that were released in the explosion, such as the kinetic

energy and potential energy of the pieces, as well as heat and sound, one will get the exact

decrease of chemical energy in the combustion of the dynamite. Classically, conservation of

energy was distinct from conservation of mass; however, special relativity showed that mass is

related to energy and vice versa by e = mc2, and science now takes the view that mass–energy as

a whole is conserved. theoretically, this implies that any object with mass can itself be converted

Partial preview of the text

Download thermodynamics and its implication and more Lecture notes Physics in PDF only on Docsity!

Thermodynamics and its Implication The laws of thermodynamics define physical quantities, such as temperature, energy, and entropy, that characterize thermodynamic systems at thermodynamic equilibrium. The laws describe the relationships between these quantities, and form a basis of precluding the possibility of certain phenomena, such as perpetual motion. In addition to their use in thermodynamics, they are important fundamental laws of physics in general, and are applicable in other natural sciences. Thermodynamics has traditionally recognized three fundamental laws, simply named by an ordinal identification, the first law, the second law, and the third law. In addition, after the first three laws were established, it was recognized that another law, more fundamental to all three, could be stated, which was named the Zeroth law. The zeroth law of thermodynamics defines thermal equilibrium and forms a basis for the definition of temperature: if two systems are each in thermal equilibrium with a third system, they are in thermal equilibrium with each other. The first law of thermodynamics: when energy passes into or out of a system (as work, as heat, or with matter), the system's internal energy changes in accord with the law of conservation of energy. Equivalently, perpetual motion machines of the first kind (machines that produce work with no energy input) are impossible. The second law of thermodynamics: in a natural thermodynamic process, the sum of the entropies of the interacting thermodynamic systems increases. Equivalently, perpetual motion machines of the second kind (machines that spontaneously convert thermal energy into mechanical work) are impossible. The third law of thermodynamics: the entropy of a system approaches a constant value as the temperature approaches absolute zero. With the exception of non-crystalline solids (glasses) the entropy of a system at absolute zero is typically close to zero. Additional laws have been suggested, but none of them achieved the generality of the four accepted laws, and are not discussed in standard textbooks. Law of conservation of energy In physics and chemistry, the law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over time.[1]^ This law first proposed and tested by émilie du châtelet, means that energy can neither be created nor destroyed; rather, it can only be transformed or transferred from one form to another. For instance, chemical energy is converted to kinetic energy when a stick of dynamite explodes. If one adds up all forms of energy that were released in the explosion, such as the kinetic energy and potential energy of the pieces, as well as heat and sound, one will get the exact decrease of chemical energy in the combustion of the dynamite. Classically, conservation of energy was distinct from conservation of mass; however, special relativity showed that mass is related to energy and vice versa by e = mc^2 , and science now takes the view that mass–energy as a whole is conserved. theoretically, this implies that any object with mass can itself be converted

to pure energy, and vice versa, though this is believed to be possible only under the most extreme of physical conditions, such as likely existed in the universe very shortly after the big bang or when black holes emit hawking radiation. Implication on Biology (Ecology) The laws of thermodynamics are important unifying principles of biology. these principles govern the chemical processes (metabolism) in all biological organisms. The first law of thermodynamics, also known as the law of conservation of energy, states that energy can neither be created nor destroyed. It may change from one form to another, but the energy in a closed system remains constant. The second law of thermodynamics states that when energy is transferred, there will be less energy available at the end of the transfer process than at the beginning. Due to entropy, which is the measure of disorder in a closed system, all of the available energy will not be useful to the organism. Entropy increases as energy is transferred. In addition to the laws of thermodynamics, the cell theory, gene theory, evolution, and homeostasis form the basic principles that are the foundation for the study of life. First Law of Thermodynamics in Biological Systems All biological organisms require energy to survive. In a closed system, such as the universe, this energy is not consumed but transformed from one form to another. Cells, for example, perform a number of important processes. These processes require energy. In photosynthesis, the energy is supplied by the sun. Light energy is absorbed by cells in plant leaves and converted to chemical energy. The chemical energy is stored in the form of glucose, which is used to form complex carbohydrates necessary to build plant mass. The energy stored in glucose can also be released through cellular respiration. This process allows plant and animal organisms to access the energy stored in carbohydrates, lipids, and other macromolecules through the production of ATP. This energy is needed to perform cell functions such as DNA replication, mitosis, meiosis, cell movement, endocytosis, exocytosis, and apoptosis. Second Law of Thermodynamics in Biological Systems As with other biological processes, the transfer of energy is not 100 percent efficient. In photosynthesis, for example, not all of the light energy is absorbed by the plant. Some energy is reflected and some is lost as heat. The loss of energy to the surrounding environment results in an increase of disorder or entropy. Unlike plants and other photosynthetic organisms, animals cannot generate energy directly from the sunlight. They must consume plants or other animal organisms for energy. The higher up an organism is on the food chain, the less available energy it receives from its food sources. Much of this energy is lost during metabolic processes performed by the producers

It follows, too, that virtually all products are really joint products, except that wastes have no positive market value. On the contrary, they have, in most cases, a negative value. A producer of wastes will need a 'sink' for disposal. Options for free disposal are becoming rarer. Producers must, increasingly, pay to have waste residuals removed and treated, safely disposed of, or recycled. The implication that there exists a price-determined equilibrium between supply and demand (of commodities) must therefore be modified fundamentally. This means, among other things, that 'externalities' (market failures) associated with production and consumption of materials are actually pervasive and that they tend to grow in importance as the economy itself grows. Materials recycling can help (indeed, it must), but recycling is energy (energy) intensive and (thanks to the second law) imperfect, so it cannot fully compensate for a declining natural resource base. Long-term sustainability must depend to a large extent upon dematerialization and 'decoupling' of economic welfare from the natural resource base. The mass-balance condition provides powerful tools for estimating process wastes and losses for industrial processes, or even whole industries, where these cannot be determined directly. Even where other data are available, the mass-balance condition offers a means of verification and interpolation, to fill in gaps. Thermodynamics and Society/Politics The second law of thermodynamics states that every isolated body becomes more disordered with time. The second law basically states that matter left to itself will decay, deteriorate, run down and die unless acted upon by an outside force. This law primarily applies to the natural, material world. Our houses need paint after a while, cars need increasing repairs as they age, our clothes wear out, things rust, and the items on my desk go from order to disorder. The First Law of Thermodynamics states that energy cannot be created or destroyed; the total quantity of energy in the universe stays the same. The Second Law of Thermodynamics is about the quality of energy. It states that as energy is transferred or transformed, more and more of it is wasted. In other words, all processes result in an increase in entropy, or disorder. A tree falls to the ground and decays. Order to disorder. A person dies and the body decays. Order to Disorder. A country is built on the strength and independence of the individual, then devolves to weakness and total dependence on an ever more dominating and controlling government. Order to Disorder. A government begins as a lean, efficient entity, and becomes overwhelmingly chaotic, contradictory and controlling of a weaker, dependent individual. Order to Disorder. A strong and independent population devolves into a weak, dependent and entitled populace. Order to Disorder. References

Buchdahl, H.A. (1966), The Concepts of Classical Thermodynamics, Cambridge University Press, London, pp. 30, 34ff, 46f, 83.
^ *Münster, A. (1970), Classical Thermodynamics, translated by E.S. Halberstadt, Wiley–Interscience, London, ISBN 0-471-62430-6, p. 22.
^ Pippard, A.B. (1957/1966). Elements of Classical Thermodynamics for Advanced Students of Physics, original publication 1957, reprint 1966, Cambridge University Press, Cambri
Alberty R (2004). "A short history of the thermodynamics of enzyme-catalyzed reactions". J Biol Chem. 279 (27): 27831–
doi:10.1074/jbc.X400003200. PMID 15073189.
^ Akihiko Ito & Takehisa Oikawa. "Global Mapping of Terrestrial Primary Productivity and Light-Use Efficiency with a Process-Based Model". In M. Shiyomi; et al. (eds.). Global Environmental Change in the Ocean and on Land (PDF). pp. 343–358.
^ M.J. Farabee. "Reactions and Enzymes". On-Line Biology Book. Estrella Mountain Community College. Archived from the original on 2012-12-28. Retrieved 2006-09-26.
^ Haynie, Donald T. (2001). Biological Thermodynamics. Cambridge University Press. pp. 1 –16.
^ Skene, Keith (July 31, 2015). "Life's a Gas: A Thermodynamic Theory of Biological Evolution". Entropy. 17 (12): 5522–5548. doi:10.3390/e17085522. S2CID 2831061.
^ Haynie, Donald T. (2001). Biological Thermodynamics. Cambridge UP. ISBN 9780521795494.
^ Stacy, Ralph W., David T. Williams, Ralph E. Worden, and Rex O. McMorris. Essentials of Biological and Medical Physics. New York: McGraw-Hill Book, 1955. Print.
^ Haynie, Donald T. Biological Thermodynamics. Cambridge: Cambridge UP, 2001. Print.
^ Bergethon, P. R. The Physical Basis of Biochemistry: The Foundations of Molecular Biophysics. New York: Springer, 1998. Print.

thermodynamics and its implication, Lecture notes of Physics

Related documents

Partial preview of the text

Download thermodynamics and its implication and more Lecture notes Physics in PDF only on Docsity!