What is the second law of thermodynamics

The already familiar direction of heat transfer from hot to cold is the basis of our first version of the second law of thermodynamics. Like all natural laws, the second law of thermodynamics gives insights into nature, and its several statements imply that it is broadly applicable, fundamentally affecting many apparently disparate processes. We shall see that the second law can be stated in many ways that may seem different, but these many ways are, in fact, equivalent. The law that forbids these processes is called the second law of thermodynamics. The first law of thermodynamics would allow them to occur-none of those processes violate conservation of energy. The fact that certain processes never occur suggests that there is a law forbidding them to occur. The random motions of the gas molecules will never return them to the corner. (c) The burst of gas let into this vacuum chamber quickly expands to uniformly fill every part of the chamber.

(b) The brakes of this car convert its kinetic energy to heat transfer to the environment. (a) Heat transfer occurs spontaneously from hot to cold and not from cold to hot.

One-Way Processed in Nature: Examples of one-way processes in nature. The random motion of the gas molecules could take them all back to the corner, but this is never observed to happen. The gas expands to fill the chamber, but it never regroups in the corner. Yet another example is the expansion of a puff of gas introduced into one corner of a vacuum chamber. A hot stationary object never spontaneously cools off and starts moving. Furthermore, mechanical energy, such as kinetic energy, can be completely converted to thermal energy by friction, but the reverse is impossible. A cold object in contact with a hot one never gets colder, transferring heat to the hot object and making it hotter. If the process can go in only one direction, then the reverse path differs fundamentally and the process cannot be reversible.ДЇor example, heat involves the transfer of energy from higher to lower temperature. More precisely, an irreversible process is one that depends on path. Although irreversibility is seen in day-to-day life-a broken glass does not resume its original state, for instance-complete irreversibility is a statistical statement that cannot be seen during the lifetime of the universe. Many processes occur spontaneously in one direction only-that is, they areirreversible, under a given set of conditions. The second law of thermodynamics deals with the direction taken by spontaneous processes. the first law of thermodynamics: A version of the law of conservation of energy, specialized for thermodynamical systems.entropy: A measure of how evenly energy (or some analogous property) is distributed in a system.According to the second law of thermodynamics, it is impossible for any process to have heat transfer from a cooler to a hotter object as its sole result.Many processes occur spontaneously in one direction only, and the second law of thermodynamics deals with the direction taken by spontaneous processes.Many thermodynamic phenomena, allowed to occur by the first law of thermodynamics, never occur in nature.

What is the second law of thermodynamics