7 Class Working Model in Physics
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Working class (or Lower class, Labouring class) is a term used in the social sciences and in ordinary conversation to describe those employed in lower tier jobs (as measured by skill, education and lower incomes), often extending to those in unemployment or otherwise possessing below-average incomes. Working classes are mainly found in industrializedeconomies and in urban areas of non-industrialized economies.
As with many terms describing social class, working class is defined and used in many different ways. When used non-academically, it typically refers to a section of society dependent on physical labor, especially when compensated with an hourly wage. Its use in academic discourse is contentious, especially following the decline of manual labor in postindustrial societies. Some academics question the usefulness of the concept of a working class.
The term is usually contrasted with the Upper classandMiddle class, in general terms of access to economic resources,education and cultural interests. The cut-off between Working class and Middle class is more specifically where a population spends money primarily as a lifestyle rather than for sustenance (for example, on fashion versus merely nutrition and shelter).
Its usage can alternately be derogatory, or can express a sense of pride in those who self-identify as Working class.
Definitions of social classes reflect a number of sociological perspectives, informed by anthropology, economics, psychology and sociology. The major perspectives historically have been Marxism and Functionalism.. The parameters which define working class depend on the scheme used to define social class. For example, a simple stratum model of class might divide society into a simple hierarchy of lower class, middle class and upper class, with working class not specifically designated. Due to the political interest in the working class, there has been debate over the nature of the working class since the early 19th century. Two broad schools of definitions emerge: those aligned with 20th-century sociological stratum models of class society, and those aligned with the 19th-century historical materialism economic models of the Marxists and anarchists. Key points of commonality amongst various ideas include the idea that there is one working class, even though it may be internally divided. The idea of one single working class should be contrasted with 18th-century conceptions of many laboring classes. Sociologists Dennis Gilbert, James Henslin, William Thompson, Joseph Hickey and Thomas Ayling have brought forth class models in which the working class constitutes roughly one third of the population, with the majority of the population being either working or lower class.
Karl Marx defined the working class or proletariat as individuals who sell their labor power for wages and who do not own the means of production. He argued that they were responsible for creating the wealth of a society. He asserted that the working class physically build bridges, craft furniture, grow food, and nurse children, but do not own land, or factories. A sub-section of the proletariat, the lumpenproletariat (rag-proletariat), are the extremely poor and unemployed, such as day laborers and homeless people.
In The Communist Manifesto, Marx argued that it was the destiny of the working class to displace thecapitalist system, with the dictatorship of the proletariat, abolishing the social relationships underpinning the class system and then developing into a future communist society in which "the free development of each is the condition for the free development of all." In Capital, Marx dissected the ways in which capital can forestall such a revolutionary extension of the Enlightenment. Some issues in Marxist arguments about working class membership have included:
In some ways we would not have computers today were it not for physics. Furthermore, the needs of physics have stimulated computer development at every step. This all started due to one man's desire to eliminate needless work by transferring it to a machine. Charles Babbage (1791â€“1871) was a well-to-do Englishman attending Cambridge University in the early 1800s. One day he was nodding off over a book containing tables of astronomical phenomena. He fancied that he would become an astronomical mathematician. The motion of heavenly bodies was, of course, governed by the laws of physics. For a moment, he thought of having the tables calculated automatically. This idea came up several times in succeeding years until he finally designed a calculator, the Difference Engine, that could figure the numbers and print the tables. A version of the Difference Engine made by someone else found its way to the Dudley Observatory in Albany, New York, where it merrily cranked out numbers until the 1920s. Babbage followed this machine with a programmable version, the Analytical Engine, which was never built. The Analytical Engine, planned as a more robust successor to the Difference Engine, is considered by many to be the first example of a modern computer. In the late 1800s, mathematician and scientist Lord Kelvin (William Thomson) (1824â€“1907) tried to understand wave phenomena by building a mechanical analog computer that modeled the waves on beaches in England. This was a continuation of the thread of mechanical computation applied to understand physical phenomena in the 1800s. In the 1920s, physicist Vannevar Bush (1890â€“1974) of the Massachusetts Institute of Technology built a Differential Analyzer that used a combination of mechanical and electrical parts to create an analog computer useful for many problems. The Differential Analyzer was especially suited for physics calculations, as its output was a smooth curve showing the results of mathematical modeling. This curve was very accurate, more so than the slide rules that were the ubiquitous calculators in physics and engineering in the first seven decades of the twentieth century. Beginning during World War II and finishing just after the war ended, the Moore School of the University of Pennsylvania built an electronic digital computer for the U.S. Army. One of the first problems run on it was a model of a nuclear explosion. The advent of digital computers opened up whole new realms of research for physicists. Physicists like digital computers because they are fast. Thus, big problems can be figured out, and calculations that are boring and repetitious by hand can be transferred to computers. Some of the first subroutines, blocks of computer code executed many times during the run of a program, were inspired by the needs of physics. Even though digital computers were fast with repetitious tasks, the use of approximation and visualization has the largest effect on physicists using electronic computers. Analog machines, both mechanical and electronic, have output that models real world curves and other shapes representing certain kinds of mathematics. To calculate the mathematical solution of physical problems on digital computers meant the use of approximation. For example, the area under a curve (the integral) is approximated by dividing the space below the curve into rectangles, figuring out their area, and adding the small areas to find the one big area. As computers got faster, such approximations were made up of an ever-increasing number of smaller rectangles. Visualization is probably the physicist's task most aided by computers. The outputs of Lord Kelvin's machine and the Differential Analyzer were drawn by pens connected to the computational components of the machine. The early digital computers could print rough curves, supplemented by cleaner curves done on a larger scale by big plotters. Interestingly, the plotters drew what appeared to be smooth lines by drawing numerous tiny straight lines, just like a newspaper photograph is really a large number of gray points with different shades. Even these primitive drawing tools were a significant advance. They permitted physicists to see much more than could be calculated by hand. In the 1960s, physicists took millions of photographs of sub-atomic particle collisions. These were then processed with human intervention. A "scanner" (usually a student) using a special machine would have the photographs of the collisions brought up one by one. The scanner would use a trackball to place a cursor over a sub-atomic particle track. At each point the scanner would press a button, which then allowed the machine to punch the coordinates on a card. These thousands upon thousands of cards were processed to calculate the mass and velocity of the various known and newly discovered particles. These were such big jobs that they were often run on a computer overnight. Physicists could use the printed output of batch-type computer systems to visualize mentally what was really happening. This is one of the first examples of truly large-scale computing. In fact, most of the big calculations done over the first decades of electronic digital computing had some relationship to physics, including atomic bomb models, satellite orbits, and cyclotron experiments. The advent of powerful workstations and desktop systems with color displays ended the roughness and guessing of early forms of visualization. Now, many invisible phenomena, such as fields, waves, and quantum mechanics, can be modeled accurately in full color. This is helping to eliminate erroneous ideas inspired by the poor visualizations of years past. Also, these computer gameâ€“quality images can be used to train the next generation of physics students and their counterparts in chemistry and biology classes, making tangible what was invisible before. Finally, the latest and perhaps most pervasive of physics-inspired computer developments is the World Wide Web. It was first developed as a way of easily sharing data, including graphics, among researchers in the European cyclotron community and also for those outside of it with appropriate interests. So whenever a browser is launched, 200 years of physics-driving computer development is commemorated. see also Astronomy; Data Visualization; Mathematics; Navigation. James E. Tomayko Merrill, John R. Using Computers in Physics. Boston: Houghton Mifflin Company, 1976.
physics branch of science traditionally defined as the study of matter , energy , and the relation between them; it was called natural philosophy until the late 19th cent. and is still known by this name at a few universities. Physics is in some senses the oldest and most basic pure science; its discoveries find applications throughout the natural sciences, since matter and energy are the basic constituents of the natural world. The other sciences are generally more limited in their scope and may be considered branches that have split off from physics to become sciences in their own right. Physics today may be divided loosely into classical physics and modern physics. Classical Physics Classical physics includes the traditional branches and topics that were recognized and fairly well developed before the beginning of the 20th cent.â€” mechanics , sound , light , heat , and electricity and magnetism . Mechanics is concerned with bodies acted on by forces and bodies in motion and may be divided into statics (study of the forces on a body or bodies at rest), kinematics (study of motion without regard to its causes), and dynamics (study of motion and the forces that affect it); mechanics may also be divided into solid mechanics and fluid mechanics, the latter including such branches as hydrostatics, hydrodynamics, aerodynamics, and pneumatics. Acoustics , the study of sound, is often considered a branch of mechanics because sound is due to the motions of the particles of air or other medium through which sound waves can travel and thus can be explained in terms of the laws of mechanics. Among the important modern branches of acoustics is ultrasonics , the study of sound waves of very high frequency, beyond the range of human hearing. Optics, the study of light, is concerned not only with visible light but also with infrared and ultraviolet radiation, which exhibit all of the phenomena of visible light except visibility, e.g., reflection , refraction , interference , diffraction , dispersion (see spectrum ), and polarization of light . Heat is a form of energy, the internal energy possessed by the particles of which a substance is composed; thermodynamics deals with the relationships between heat and other forms of energy. Electricity and magnetism have been studied as a single branch of physics since the intimate connection between them was discovered in the early 19th cent.; an electric current gives rise to a magnetic field and a changing magnetic field induces an electric current. Electrostatics deals with electric charges at rest, electrodynamics with moving charges, and magnetostatics with magnetic poles at rest. Modern Physics Most of classical physics is concerned with matter and energy on the normal scale of observation; by contrast, much of modern physics is concerned with the behavior of matter and energy under extreme conditions or on the very large or very small scale. For example, atomic and nuclear physics studies matter on the smallest scale at which chemical elements can be identified. The physics of elementary particles is on an even smaller scale, being concerned with the most basic units of matter; this branch of physics is also known as high-energy physics because of the extremely high energies necessary to produce many types of particles in large particle accelerators . On this scale, ordinary, commonsense notions of space, time, matter, and energy are no longer valid. The two chief theories of modern physics present a different picture of the concepts of space, time, and matter from that presented by classical physics. The quantum theory is concerned with the discrete, rather than continuous, nature of many phenomena at the atomic and subatomic level, and with the complementary aspects of particles and waves in the description of such phenomena. The theory of relativity is concerned with the description of phenomena that take place in a frame of reference that is in motion with respect to an observer; the special theory of relativity is concerned with relative uniform motion in a straight line and the general theory of relativity with accelerated motion and its connection with gravitation. Both the quantum theory and the theory of relativity find applications in all areas of modern physics. Evolution of Physics Greek Contributions The earliest history of physics is interrelated with that of the other sciences. A number of contributions were made during the period of Greek civilization, dating from Thales and the early Ionian natural philosophers in the Greek colonies of Asia Minor (6th and 5th cent. BC). Democritus (c.460-370 BC) proposed an atomic theory of matter and extended it to other phenomena as well, but the dominant theories of matter held that it was formed of a few basic elements, usually earth, air, fire, and water. In the school founded by Pythagoras of Samos the principal concept was that of number; it was applied to all aspects of the universe, from planetary orbits to the lengths of strings used to sound musical notes. The most important philosophy of the Greek period was produced by two men at Athens, Plato (427-347 BC) and his student Aristotle (384-322 BC); Aristotle in particular had a critical influence on the development of science in general and physics in particular. The Greek approach to physics was largely geometrical and reached its peak with Archimedes (287-212 BC), who studied a wide range of problems and anticipated the methods of the calculus. Another important scientist of the early Hellenistic period, centered in Alexandria, Egypt, was the astronomer Aristarchus (c.310-220 BC), who proposed a heliocentric, or sun-centered, system of the universe. However, just as the earlier atomic theory had not become generally accepted, so too the astronomical system that eventually prevailed was the geocentric system proposed by Hipparchus (190-120 BC) and developed in detail by Ptolemy (AD 85-AD 165). Preservation of Learning With the passing of the Greek civilization and the Roman civilization that followed it, Greek learning passed into the hands of the Muslim world that spread its influence from the E Mediterranean eastward into Asia, where it picked up contributions from the Chinese (papermaking, gunpowder) and the Hindus (the place-value decimal number system with a zero), and westward as far as Spain, where Islamic culture flourished in CÃ³rdoba, Toledo, and other cities. Little specific advance was made in physics during this period, but the preservation and study of Greek science by the Muslim world made possible the revival of learning in the West beginning in the 12th and 13th cent. The Scientific Revolution The first areas of physics to receive close attention were mechanics and the study of planetary motions. Modern mechanics dates from the work of Galileo and Simon Stevin in the late 16th and early 17th cent. The great breakthrough in astronomy was made by Nicolaus Copernicus, who proposed (1543) the heliocentric model of the solar system that was later modified by Johannes Kepler (using observations by Tycho Brahe) into the description of planetary motions that is still accepted today. Galileo gave his support to this new system and applied his discoveries in mechanics to its explanation. The full explanation of both celestial and terrestrial motions was not given until 1687, when Isaac Newton published his Principia [Mathematical Principles of Natural Philosophy]. This work, the most important document of the Scientific Revolution of the 16th and 17th cent., contained Newton's famous three laws of motion and showed how the principle of universal gravitation could be used to explain the behavior not only of falling bodies on the earth but also planets and other celestial bodies in the heavens. To arrive at his results, Newton invented one form of an entirely new branch of mathematics, the calculus (also invented independently by G. W. Leibniz), which was to become an essential tool in much of the later development in most branches of physics. Other branches of physics also received attention during this period. William Gilbert, court physician to Queen Elizabeth I, published (1600) an
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Answers:Can you get hands on pulleys ? Pulley systems relatively easy to set up and awesome demonstration of Lever type system. If set up right (firm ring stand or mounted) they can lift quite interesting amounts of weight with little force. Perfect for "Work and Energy" in Class IX physics. Web site might give some help if you are in India ?