Transfer of heat from the system to its environment is spontaneous if entropy production is positive, requiring that the system has a higher temperature. Pdf abiogenesis and the second law of thermodynamics. In a nonadiabatic process, the change in energy is equal to the heat added to the system minus the mechanical work done by the system. Why it is important to formulate the law for open systems can be illustrated with fig.
Heat engines, entropy, and the second law of thermodynamics. Choosing a clever system is half the solution of many thermodynamical problems. Chapter 5 2 thermal energy reservoir a thermal energy reservoir is a hypothetical body that can supplyor absorbfinite amounts of heat without undergoing any change in temperature large bodies of. Describe the kelvinplanck and clausius statements of the second law of thermodynamics. Sadi carnot, founder of the second law of thermodynamics.
The lecture handouts are available in the table below. The first law places no restriction on the direction of a process, and satisfying the first law. The second law of thermodynamics for the free expansion, we have. As motivation for the development of the second law, we examine two types of processes that concern interactions between heat and work. Gases expand from a high pressure to a low pressure. Thus for given values of t2 and qa, qr depends only on the temperature of the cold reservoir t1, which is limited by.
To be able to use the first law of thermodynamics to estimate the potential for thermomechanical energy conversion in aerospace power and propulsion systems. The focus of the lecture is the concept of entropy. In the second law work and heat are treated in an essentially di. The second law also asserts that energy has a quality. The part of universe for study is called system and remaining portion is surroundings. Second law of thermodynamics and entropy reversibility and the second law figure 1. Thermodynamics laws in pdf notes zeroth law second law 3rd law. A process cannot take place unless it satisfies both the first and second laws of thermodynamics. Boltzmanns microscopic formula for entropy is introduced and used to explain irreversibility.
Physical processes in nature can proceed toward equilibrium spontaneously. The first, second, and third law of thermodynamics. The second law of thermodynamics states that the total entropy of an isolated system can never decrease over time, and is constant if and only if all processes. The first law of thermodynamics is a statement about energy conservation, while the second is a statement about stable thermal equilibrium. One carnot cycle consists of four consecutive thermodynamic processes, which can be realized with an arbitrary working substance.
In this pictorial representation, the system is shown qualitatively with an original enthalpy and entropy. A process can occur when and only when it satisfies both the first and the second laws of thermodynamics. The first law of thermodynamics is a statement of the principle of. Science which deals with study of different forms of energy and quantitative relationship. However, those contents do not necessarily represent the policy of fipse and the department of education, and. At the time when carnot lived, the first law of thermodynamics, the conservation of energy, was not known. The second law of thermodynamics the second law of thermodynamics asserts that processes occur in a certain direction and that the energy has quality as well as quantity. Phys 200 lecture 24 the second law of thermodynamics. Preserving the quality of energy is a major concern of engineers. Some of this material is quite challenging, be sure to read this material carefully. The second, which is much more useful, concerns the conversion of heat into work. For the reversible isothermal process, for the gas. Chapter 6 lecture second law of thermodynamics heat. Thermodynamics thermodynamics the first law of thermodynamics.
The first law of thermodynamics lecture 6 prereading. The first of these represents the conversion of work into heat. Which means the energy neither be created nor it can be destroyed. The second law of thermodynamics is one of the thermodynamic laws from the three laws of thermodynamics. Heat is a form of energy that flows from warmer to cooler objects 1st and 2nd law of thermodynamics crucial for understanding all sciences. The laws of thermodynamics are deceptively simple to state, but they are farreaching in their consequences. In a famous lecture entitled the two cultures given in 1959, the novelist c.
The second law of thermodynamics the second law of thermodynamics states that processes occur in a certain direction, not in just any direction. In this case the second law is a conservation law with. Lecture notes section contains the class notes files. Another example that comes to mind is the more recent analysis of information theory by claude shannon. Our second law incorporates part of the conventional third law of thermo. Relate to the 1st law of thermodynamics thermal expansion cracking the nut. Where the first law states about the quantity of energy. In this part, we introduce the second law of thermodynamics, which asserts that processes occur in a certain direction and that energy has quality as well as quantity. Thermodynamics laws in pdf notes zeroth law second law 3rd. Second law of thermodynamics a process will not occur unless it satisfies boththe first and the second laws of thermodynamics spring 2003 ece309.
The second law of thermodynamics and statistical mechanics. One way of stating the second law of thermodynamics is. Lecture 14 chapter 19 ideal gas law and kinetic theory of gases chapter 20 entropy and the second law of thermodynamics now we to look at temperature, pressure, and internal energy in terms of the motion of molecules and atoms. Entropy and the second law of thermodynamics youtube. Pdf lecture 7 the second law of thermodynamics and heat. The second law of thermodynamics has several consequences regarding the.
The socalled second law of thermodynamics was thus discovered by carnot before the first law. No process is possible in which the sole result is the absorption of heat from a reservoir and its. We will introduce the rst and second law for open systems. Work and efficiency as motivation for the development of the second law, we examine two types of processes that. The first law asserts that if heat is recognized as a form of energy, then the total energy of a system plus its surroundings is conserved. The entropy of an isolated system can only increase. Heat and the second law of thermodynamics chapter4great idea. The second law of the thermodynamics, we are going to talk about the quality. Pdf a new statement of the second law of thermodynamics is given.
The carnot process is a reversible cycle process bounded by two isotherms and two adiabatic lines. The increase of the internal energy of a system is equal to the sum of the heat added to the system plus the work done on the system. Apply the second law to develop the absolute thermodynamic temperature scale. Second law of thermodynamics no engine, working in a continuous cycle, can take heat from a reservoir at a single temperature and convert that heat completely to work. Specific examples are given to calculate the entropy change for a. The second law is commensurate with chemical evolution, but is incapable of explaining the mechanism behind the. The second law of thermodynamics has several consequences regarding the carnot cycle. Lecture 14 ideal gas law and terms of the motion of. One correct statement of the second law of thermodynamics is. Chapter 4 entropy and the second law of thermodynamics.
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