D2 Measurong Youngs modulus of copper Essays

D2 Measurong Youngs modulus of copper Essays D2 Measurong Youngs modulus of copper Paper D2 Measurong Youngs modulus of copper Paper In this experiment, The Youngs modulus of copper will be mesured . Apparatus copper wire 4m G-clamp polley on clamp -2*Wooden block 2*rule (half meter and meter rule) slotted mass with hanger 15 Â  0. 1 kg adhesive label -micrometer screw gauge -safety goggles -polystyrene board (Warning : Wear safety goggles when doing this experiment ) Theory When a spring is stretched or compressed by a force. The extension is directly proportional to the applied force. This relationship known as Hookes law. Force=ke. However,the law is used when the proportional limit is not exceeded. To further investigate how the material behaves when it is stressed,we define: The stress applied to the wire is defined as the force applied per unit cross-sectional area. Stress = force per unit area =F/A (where F is the force or tension in the wire, A is the cross-sectional area) When the wire being stretched,it is under strain. The strain is defined as the extension per unit length. Strain = extension per unit length = e/l (where e is the extension and l is the unstretched length of the wire) Withon the proportional limit,the ration stress/strain is a constant whose value depends on the material of the wire. It is known as the Young modulus of the material E = stress/strain = (F/A)/(e/l) = Fl/Ae From this law,a material with larger Youngs modulus means a greater stress is required to produce the same strain than another material with smaller Youngs modulus gives how stiff a material is. In this experiment, we will hang different loads (m) to one end of a copper wire of length l and diameter d. The extension (e) for each load is measured. From the slope of the straight part of the m-e graph, Youngs modulus of copper can be found. Since F=mg and A= cross-sectional area of the wire = ? (d/2)2 = ? d2/4, Youngs modulus of the copper wire is given by E = Fl/Ae = mgl/(? d2/4)e = m/e x 4gl/? d2 = slope of graph x 4gl/? d2 Procedure 1. To measure the diameter of the wire at two end and the center of the wire by using a micrometer screw gauge to take the mean value of the diameter. 2. The apparatus is seted on the bench as shown in Fig. D2. 1. 3. Fix an adhesive label on the copper wire as a marker 4. Measure the unstretched original length of the wire before addong slotted mass to the wire (from the wooden blocks to the slotted mass) 5. The copper was loaded in steps and the extension produced was recorded. Steps were continued until the wire broke Results 1st measurement 2nd measurement 3rd measurement . 2 1. 3 1. 4 0. 0042 0. 005 0. 007 0. 009 0. 015 0. 036 0. 087 0. 155 Before the load increase to 0. 7 kg. The extension is nearly proportional to the force . Also stress is nearly proprtional to strain. After the load is beyond 0. 7kg,extension is not proportional to force and stree is not proportional to strain. The plastic deformation occur. The wire does not return completely to its original length . The wire broke whn the load is increase to 1. 4 kg. This part of graph obeys Hookes law. Fig. 4 % strain = extension / original length x 100% = 0. 0042/ 3. 95x 100% = 0. 106% Fig. 4 shows the best straight line through the points of the straight part of the graph. Slope of load-extension graph = 189. 72 kgm-1 Youngs modulus of copper E = slope of graph x 4gl/? d2 =189. 72 x 4(10)(3. 95)/? (0. 000278)2 =123. 46109 Pa Error estimation Sraw lines of maximum and minimum slope through the points of the graph. Find the slope and take the large deviation from the slope of the fitted graph as the error Maximum slope = 208. 77 Minimum slope = 163. 15 Error in slope = i 26. 57 % error in slope =14.00 % Estimate the possible errors in l and d and express them as percentages Error in l = 0. 1cm/2 = i 0. 05cm % error in l =0. 0127% Error in d = i 0. 005mm %error in d = 0. 0180% Hence, estimate the % error in E. % error in E = % error in slope + % error in l + 2 i % error in d = 14. 00% + 0. 0127% + 2 i 0. 0180% = 14. 049% Error in E = i 1. 7345i 1012 Discussion From the graph of Fig. 4 . The wire is undergo a proportional limit before the load increase to 0. 7 kg. Its obeys Hookes law. When the load is not reach to a yield point. The wire can returns to its original length when the load is removed. In this graph . The slope of the graph of load against extension determines the Youngs modulus. When the load is beyond the yield point. The plastic deformation will occur. The wire does not return completely to its original length . It will contain a permanent extension. Then the load is added to the wire continuously. The extension of the wire is more signifiance.. The wire narrows uniformly. In our experiment,The maximum stress at the breaking point. Break is due to the wire narrows unevenly to form necks. There are some precautions for this experiment. When we read the value of the length of the wire. It is more accuracy as we observe the value vertically. Moreover,when the load is add on the wire. It is more suitable to add slowly. This can avoid the force added by our hand. Besides,students should wear safety goggles when doing this experiment. It can protect our eye is hited by the wire. Youngs modulus is more useful than force constant because the Youngs modulus depend on the force per unit cross sectional area. Also,the extension is per unit length. It is more accuracy than the force constant which is only depend on the relationship between the force and extension. From the book called NEW WAY PHYSICS. the youngs modulus of the copper is 124109 Pa. Also from answers. com/topic/young-s-modulus. the Youngs modulus is between110 to 130 x109 Pa. Compare with our result. It is 124109 Pa. The answer is very close to the reference answer. It is because we take all of the value very carefullyand seriously for decrease the error. Conclusion The Youngs modulus is depend on the materials. The Young modulus of copper which measure by our group is 124109 Pa.

20 Controversial Essay Topics Hot Issues on Human Rights as a Form of Imperialism

20 Controversial Essay Topics Hot Issues on Human Rights as a Form of Imperialism If you are looking for a potential topic for your controversial essay on Human Rights as a Form of Imperialism, then look no further. Below are some sample essay topics that might be suitable for your next writing assignment. Remember that these are only meant to guide you and in some cases they may not be the most suitable selections depending on the guidelines of your assignment: Natural Law and Human Rights Violations Which Governments Use Human Rights as a Form of Imperialism How China Restricts Modern Internet Access to Control Tibet French Imperialistic Traces in Former Colonial Governments How North Korea Uses Limited Teaching, Talking About Threats to the Government, Helping Foreigners and Possessing Books Deemed Wrong as Imperialist Control Methods Portuguese Imperialistic Traces in Former Colonial Governments Governments Surveying Nations and Peoples They Deem as Threat: Human Rights as a Form of Imperialism Comprehensive Surveillance Used as Imperialistic Human Rights Control Measures Dutch Imperialistic Traces in Former Colonial Human Rights as a Form of Imperialism The Use of Continual Communications Monitoring in Businesses as Imperialistic Human Rights Control Measures Corporate Contributions to Western Politicians as Imperialistic Human Rights Control Measures British Imperialistic Traces in Former Colonial States: Human Rights as a Form of Imperialism Companies Using Advertisements to Control News as Imperialistic Human Rights Control Measures Asian Communities and Regimes Using Imperialistic Human Rights as Control Measures Japanese Imperialistic Traces in Former Colonial Governments Prominent Displays of Imperialistic Human Rights Control Measures in Modern Countries Complete International Media Control as Imperialistic Human Rights Control Measure Limited Information Availability as Imperialistic Human Rights Control Measure Belgian Imperialistic Traces in Former Colonial Governments Prevalence of Communication Monitoring as an Imperialistic Human Rights Control Measure These topics are specially designed for you to use together with   our 10 facts on human rights as a form of imperialism with a complete guide on this rare kind of academic work. Below is a sample essay on one of those topics to help give you a better idea of what your controversial essay should really be focused on: Sample Controversial Essay on Natural Law and Human Rights Violations Natural law is a theory of ethics, a theory of politics, religious morality, and civil law. The theory of natural law in terms of ethics can be applied to law, religion, and politics. In essence, natural law is determined by the universe, or human nature. It is most often referred to as the rules which guide moral behavior. Positive law is considered man made while natural law is that which is determined by nature. As such, natural law is a major component of critiquing positive law. Positive cannot be created or known without the foundation of natural law. As such, natural law can be used to determine legal statutes under natural rights or natural justice. Natural law states that certain rights are universally recognized by human nature. English common law, for example, has been greatly affected by natural law thanks to philosophers of the time including Thomas Hobbes and John Locke. Natural law plays a large role within natural rights and is a major component of the Declaration of Independence as well as the United States Constitution. Aristotle emphasizes the difference between nature and law. Law can vary in its command from place to place while nature remains the same in all places. As such, the law of nature was posed as a form of natural justice. Aristotle was said to be the father of natural law (Shellens, 1959, p. 77). Aristotle posits that natural justice is a subsidiary of political justice which should be established within a political community. Socrates argued that law is merely a matter of contract which binds those states men to their duty and to justice. Machiavelli argued that virtu’, even whilst occupying the role of a statesman, is circumstantial; that the best or just action might be considered unjust but is still serving the best interests. Machiavelli was a Western philosopher who was influenced by Greek philosophers such as Plato. Nonetheless, Machiavelli often argues against the philosophy of Plato. Plato believed in rulers who would rule based in moral virtue, which is defined by natural law or rather, guided by natural law. Machiavelli, conversely, believes in what he deemed â€Å"virtu† and suggested that what should be done is whatever was in the best interest of this, natural law aside. Plato speaks of the orderly universe in which we live. In The Republic, Plato suggested that ethics and politics overlapped in terms of their essential features and were, more or less, the same. He did not distinguish between public life and private life, as we do today. No private life was ever kept from the public during his time. During the time of Machiavelli, the reason for the state was to serve the people, not for the people to serve the state. Machiavelli believed that a ruler’s only purpose was making war and protecting citizens from other states’ attacks. This would mean only protecting the natural rights of the citizens of the country, even if it came at the cost of violating the natural rights of other citizens from another country. As such, a ruler was justified in acting in whatever fashion was necessary to maintain the country, even if said act was unjust. Plato argued that a ruler could never be unjust and could never violate natural law. Plato is against the ruler who rules based only on might, as seen in The Republic, and supportive of the idea of natural law or natural human rights. Socrates remained bound by an interest in ethics and natural law. He stated that knowledge gained by an individual is what makes for a good life. Knowledge is strongly identified as virtue. Thereby, if a person can obtain knowledge he or she can also obtain virtue and as such, one can teach virtue, particularly one who is in a position of authority as a leader. Knowledge of natural law would lead to an understanding that certain rights and justices are as natural as human nature and the universe and a continued education in such theory would show leaders and individuals involved in government that these were to remain as such. This creates a foundation for any political and economic system. Since the notion of private and public life being separate entities was not a popular one, Socrates stated that a person must seek knowledge prior t o seeking private interests because knowledge served as the only path to making decisions concurrent with natural law. References: Al-Jubouri, Firas A. J.  Milestones On The Road To Dystopia. Newcastle Upon Tyne, UK: Cambridge Scholars Publishing, 2014. Print. Bergman, Edward F, and William H Renwick.  Introduction To Geography. Upper Saddle River, N.J.: Prentice Hall, 1999. Print. Cortina Orts, Adela.  Covenant And Contract. LLeuven, Belgium: Peeters, 2003. Print. Larkin, Emma.  Finding George Orwell In Burma. New York: Penguin Press, 2005. Print. Larkin, Emma.  Secret Histories. London: John Murray, 2004. Print. Saccarelli, Emanuele, and Latha Varadarajan.  Imperialism Past And Present. Print. Spring, Joel H.  The American School : A Global Context. Print. Zhu, Qian et al.  The Politics Of Everyday Life: Non-Party Leftists In Republican China, 1919-1937. 2011. Print.

Compare and contrast aspects of psychodynamic and cognitive Essay

Compare and contrast aspects of psychodynamic and cognitive theoretical approaches to counselling - Essay Example Traumatic memories of childhood are recorded in the unconscious mind and these are reminded in the individual until it becomes a cause of sickness and emotional disorders in adulthood. The belief that psychological factors can cause some sickness or malfunctioning became a popular concept during the time of Freud. Freud became phenomenal when he first announced the science of psychoanalysis. It was new then but his patients were healed and freed of their illnesses because of his precise diagnosis. Although his theory focused more on the sexual libido and the oedipal complex, they were at first unopposed and became the basis for treatment of many illnesses. Stress or anxiety, according to Freud, was a primary cause of sickness in man. Riley says that these unconscious events of the pasts were discovered through â€Å"techniques such as free association, the interpretation of dreams, thoughts and feelings emerging through reveries on the couch and nothing slips of the tongue (known as ‘Freudian slips’), misreadings and the forgetting of names† (Riley, p. 5). ... Stress can mean anxiety, arousal, fear, or burnout. This particular phenomenon causes maladies like mental illness, cancer, cardiovascular disease, but also common cold. There is a relational link between arousal and stress to metabolic rate. When we are active, or involved in sports, our metabolic rate rises, along with gross measures of the heart and respiratory rates. When stress is experienced, metabolic rate also rises. Ways to determine if an organism is activated or aroused include physiological measure, where the â€Å"organism’s overt behaviour may be used as basis for evaluation† (Pargman, 2006, p. 3). We can measure or observe the physiological component. We have the nervous system which is composed of the central nervous system and the autonomic nervous system. The central nervous system is comprised of the brain, spinal cord and its branches. The automatic nervous system is composed of the head, pelvic, and sympathetic divisions. The three divisions of the autonomic nervous system are in counterbalancing act. They have some control on the vital functions of the body. The central nervous system on the other hand interferes in cases of emergency – it sends impulses to the autonomic system as soon as it perceives danger. The perception of fear in particular situations can provide thoughts. For example, a musician may think that he/she will not be able to perform well; she becomes afraid. This will send impulses to the brain. Anxiety may come in and the performance will be greatly affected. There are theoretical perspectives in determining stress causality, these are: psychoanalytic orientations, learning orientations, sociological orientations, and personological orientations (Pargman, 2006, p. 30). Freud called traumatic anxiety the excess libido