Cry, The Beloved Country By Alan Paton Reconciliation

South Africa felt the influence from a multitude of European nations before finally becoming a colony of England in the early nineteenth century. While the European population remained minute, they controlled a vast share of the wealth after manipulating the black population leaving most in poverty. Consequently, this system led to situations erupting into violence as the black population demanded equality in all aspects. Some of the Europeans were supportive of the black movement, but many lived in segregated areas and were blissfully ignorant of black’s conditions. Despite the violence depicted amongst the whites and blacks of South Africa, in Cry, The Beloved Country by Alan Paton reconciliation and the spirit of unity present†¦show more content†¦Furthermore, the writings reveal to him his lack of knowledge of Arthur and how little he was ever involved in his life. To compensate for this lost time he carries out many acts such as this one; â€Å"Do all the things you and Arthur wanted to do. If you like to call it the â€Å"Arthur Jarvis Club,† I’ll be pleased†¦Young Harrison turned it over to look at the cheque underneath† (247). Jarvis provides one thousand pounds for a club to be set up in order to help less fortunate blacks. He tries to give back to the community in his own way to honor his son’s work and even suggests that the club be named for his son. The deeds James Jarvis performs are his way of forgiving himself for never taking notice of the black’s dire situation and not being there during his son’s life. Self-reconciliation is difficult for most people, but once accomplished people can proceed onto matters concerning others. Once James Jarvis and Stephen Kumalo forgive themselves they are able to look to others and begin to reconcile with them. By happenstance, one night Jarvis and Kumalo meet each other and Jarvis explains, â€Å"I have heard you ... There is no anger in me†¦ He went in and brought her out with him. This old man, he said in English, has come to inquire about the daughter of a native† (214-215). After the shock of losing his son, James Jarvis comes to the realization that it is unfair to hold Stephen Kumalo responsible for the actions of his son. When they meet that night; JarvisShow MoreRelatedCry the Beloved Country Analysis1006 Words   |  5 PagesSummer Assignment Topic A - Cry, the Beloved Country   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Alan Paton’s work is significant in that it highlights and analyzes, from both white and black perspective, the racial boundary and its effect on society as a whole. This boundary, as Paton emphasizes, has a diverse affect on different groups of people, as well as individuals. The way that those individuals react, in Paton’s book, defines whether or not those individuals are viewed as the enemy or the victim. While their initialRead MoreThe Black Natives By Arthur Jarvis1449 Words   |  6 Pageseverything in the country, in essence capturing the natives. The natives are suppressed with low paying and hard jobs, little to no education, and essentially no social structure. Without this education, the natives learn and obtain little to no skills. Without good paying jobs, they have no wealth or prosperity. Arthur Jarvis says, â€Å"It is not permissible to watch its destruction, and to replace it by nothing, o r by so little, that a whole people deteriorates, physically and morally† (Paton 179). JarvisRead MoreAlan Paton s Cry, The Beloved Country1747 Words   |  7 Pagesdevastating impacts of fear in slavery, Stalin’s brutal reign over Russia, and most significantly, the Nazi party. Fear has constantly been shown to possess and control people to engender dire consequences, much like it does in Alan Paton’s novel Cry, the Beloved Country. In his novel, Paton examines the negative impacts of fear, namely prejudice and corruption. Set in South Africa, the main character, reverend Stephen Kumalo, observes the stark contrast between his poor village and the cosmopolitan city

The Impact of the First Europeans to the Native Cultures...

The first Europeans arrived in North America in the fifteenth century CE. Native cultures included the Olmec, the Maya, the Aztecs, the Incas, the Mound Builders of the Mississippi region, and the Anasazi of the American Southwest. The first metropolis in Mesoamerica, was the city of Teotihuacan, capital of an early state about thirty miles northeast of Mexico City that arose around the third century B.C.E. and flourished for nearly a millennium until it collapsed under mysterious circumstances. Among the groups moving into the Valley of Mexico after the fall of Teotihuacan were the Mexica. Folk legend held that their original homeland was the island in the lake called Aztlan, from that is why today they are known as the Aztecs. The Aztecs were excellent warriors. They set out to bring the entire region under their domination. For the remainder of the fifteenth century, the Aztecs took control over much of which is known as modern Mexico, from the Atlantic to the Pacific Ocean and as far south as the Guatemalan border. The Chimor kingdom was eventually succeeded in the late fifteenth century by an invading force from the mountains far to the south. The Inka were a small community in the area of Cuzco, a city located at an altitude of ten thousand feet in the mountains of southern Peru. In the 1440s, under the leadership of their powerful ruler Pachakuti, the Inka launched a campaign of conquest that eventually brought the entire region under their authority. Under hisShow MoreRelatedThe Cultural Impacts Of The Columbian Exchange775 Words   |  4 Pagesa significant impact of the modern history of the world. It completely shaped the world humans live in today, from the languages they speak, to the nations they live in, to the food they eat. (shmoop.com) The ideas, people, goods, and diseases spread during the Columbian Exchange diversified the world culturally, biologically, and economically. The Columbian Exchange made a considerable impression on the culture of many countries at the time. One major example is the cultural impact made from theRead MoreThe Columbian Exchange : A World Drift That Carried The Old And New World907 Words   |  4 Pagesanimal, plants, culture including slaves, diseases, and ideas between the eastern and western hemispheres. The exchange was the most significant event concerning ecology, agriculture, and culture in history. The Europeans were the first who touched the shores of the Americas. Old World crops such as wheat, barley, rice, and turnips had not traveled west across the Atlantic. The New World crops such as maize, white potatoes, sweet potatoes, and manioc had not traveled east to Europe. Americas did not haveRead MoreAmerican Indians And Europeans Americans958 Words   |  4 PagesAmerican Indians verses Europeans Europeans came over to America in 1492 changing the way the Natives lived forever. These natives were living peaceful and happy lives. The Europeans came over to these innocent people’s land who were minding their own business; calling them savages, killed their people, and destroying the perfect lives they once had. There are many accounts recorded on how the Indians and Europeans felt about the discovery of America. The Natives believed they had a very sophisticatedRead MoreChapter Three : Consequences Of Colonialism1747 Words   |  7 Pagesin the Americas were various- to build a new society, to promote Christianity, to acquire riches, or, as early colonists in New England expressed it, to secure a ‘competencie’ ; they all faced the same challenges of establishing themselves in an alien environment that would require them readjust and respond to new circumstances. It would be justifiable to submit that the main consequences of colonialism were largely detri mental for the native population. The colonisation of the Americas throughoutRead MoreAmerica Before Columbus And The Columbian Exchange1597 Words   |  7 PagesIn modern America, we often take for granted the natural world that surrounds us and the American culture which is built upon it. For many of us, we give little thought to the food sources that sustain and natural habitats that surround us because when viewed for what they are, most people assume that they have â€Å"simply existed† since the country was founded. However, the documentary ‘America Before Columbus’ provided this writer an extremely interesting record of how the America we know came toRead MoreWhat Was The Columbian Exchange? Essay1618 Words   |  7 PagesColumbus set out on his first voyage for Spain in search of a direct water route across the Atlantic Ocean from Europe to Asia. Instead though, he found the Americas. Once in the New World Columbus ran into a native people and decided to name them Indians. This accidental finding of the Americas ignited the first contact ever between the Western and Eastern hemisphere. The result of this was The Columbian Exchange in which there was a large trade of animals, plants, technology, culture, slaves, diseasesRead MoreChristopher Columbus and the Subjugation of the Natives639 Words   |  3 PagesChristopher Columbus and the Subjugation of the Natives Among the more notorious dimensions of the age of exploration and colonization is the impact which this massive wave of maritime transmigration would have on the indigenous populations of those locations where European settlers made landfall. And perhaps no historical figure is as emblematic of this impact than Christopher Columbus, who in his ambition to bring gold, spices and cotton home from the lands he believed to be the West Indies, wouldRead MoreThe Colonization Of Native Americans1377 Words   |  6 Pages000 years ago the first people set foot in the Americas, and it is not until 1492 that the â€Å"first people† make their way as well. The Europeans walked in and saw the Natives as the wildlife of the region and considered themselves the founders, and the Native Americans were heavily influenced and conflicted with the tidal wave of European colonization. Following the arrival of Christopher Columbus in 1492, colonization of Native American territory began. Afterwar ds, life for Native Americans becameRead MoreImpact Of The Columbian Exchange909 Words   |  4 Pagesthe Americas, Africa, and Europe. Examples of products that the Americas contributed are turkey, squash, and potatoes. Examples of products that Europe contributed are horses, sugar, and smallpox. Columbian exchange was a huge impact on our modern day world because it changed war and hunting, it introduced new ingredients to different parts of the world, it welcomed new diseases to different parts of the world and the beginning of worldwide trade set the tone for other countries. The first reasonRead MorePositive Impact Of Christopher Columbus s Discoveries1247 Words   |  5 Pages Positive Impact of Christopher Columbus’s Discoveries The world is a better place because of Christopher Columbus’ important discoveries in the New World. His explorations resulted in the vast expansion of property for Europe, the exchange of goods and cultures between countries and a change in the worldview of geography. Columbus’s explorations were the catalyst for unprecedented trade known as the Columbian Exchange, which started the exchange of goods and ideas that would last for centuries

Applied Electricity Lecture Notes Free Essays

string(44) " are also taken as complex, as given above\." Module 4 Single-phase AC Circuits Version 2 EE IIT, Kharagpur Lesson 13 Representation of Sinusoidal Signal by a Phasor and Solution of Current in R-L-C Series Circuits Version 2 EE IIT, Kharagpur In the last lesson, two points were described: 1. How a sinusoidal voltage waveform (ac) is generated? 2. How the average and rms values of the periodic voltage or current waveforms, are computed? Some examples are also described there. We will write a custom essay sample on Applied Electricity Lecture Notes or any similar topic only for you Order Now In this lesson, the representation of sinusoidal (ac) voltage/current signals by a phasor is first explained. The polar/Cartesian (rectangular) form of phasor, as complex quantity, is described. Lastly, the algebra, involving the phasors (voltage/current), is presented. Different mathematical operations – addition/subtraction and multiplication/division, on two or more phasors, are discussed. Keywords: Phasor, Sinusoidal signals, phasor algebra After going through this lesson, the students will be able to answer the following questions; 1. What is meant by the term, ‘phasor’ in respect of a sinusoidal signal? 2. How to represent the sinusoidal voltage or current waveform by phasor? 3. How to write a phasor quantity (complex) in polar/Cartesian (rectangular) form? 4. How to perform the operations, like addition/subtraction and multiplication/division on two or more phasors, to obtain a phasor? This lesson forms the background of the following lessons in the complete module of single ac circuits, starting with the next lesson on the solution of the current in the steady state, in R-L-C series circuits. Symbols i or i(t) Instantaneous value of the current (sinusoidal form) I Im ? Current (rms value) Maximum value of the current Phasor representation of the current Phase angle, say of the current phasor, with respect to the reference phasor I Same symbols are used for voltage or any other phasor. Representation of Sinusoidal Signal by a Phasor A sinusoidal quantity, i. e. current, i (t ) = I m sin ? t , is taken up as an example. In Fig. 13. 1a, the length, OP, along the x-axis, represents the maximum value of the current I m , on a certain scale. It is being rotated in the anti-clockwise direction at an angular speed, ? , and takes up a position, O A after a time t (or angle, ? = ? t , with the x-axis). The vertical projection of OA is plotted in the right hand side of the above figure with respect to the angle ? It will generate a sine wave (Fig. 13. 1b), as OA is at an angle, ? with the x-axis, as stated earlier. The vertical projection of OA along y-axis is OC = AB = Version 2 EE IIT, Kharagpur i (? ) = I m sin ? , which is the instantaneous value of the current at any time t or angle ? . The angle ? is in rad. , i. e. ? = ? t . The angular speed, ? is in rad/s, i. e. ? = 2 ? f , where f is the frequency in Hz or cycles/sec. Thus, i = I m sin ? = I m sin ? t = I m sin 2? ft So, OP represents the phasor with respect to the above current, i. The line, OP can be taken as the rms value, I = I m / 2 , instead of maximum value, Im . Then the vertical projection of OA, in magnitude equal to OP, does not represent exactly the instantaneous value of I, but represents it with the scale factor of 1 / 2 = 0. 707 . The reason for this choice of phasor as given above, will be given in another lesson later in this module. Version 2 EE IIT, Kharagpur Generalized case The current can be of the form, i (t ) = I m sin (? t ? ? ) as shown in Fig. 13. 1d. The phasor representation of this current is the line, OQ, at an angle, ? may be taken as negative), with the line, OP along x-axis (Fig. 13. 1c). One has to move in clockwise direction to go to OQ from OP (reference line), though the phasor, OQ is assumed to move in anti-clockwise direction as given earlier. After a time t, OD will be at an angle ? with OQ, which is at an angle ( ? ? ? = ? t ? ? ), with the line, OP along x-axis. The vertical projection of OD along y-axis gives the insta ntaneous value of the current, i = 2 I sin (? t ? ? ) = I m sin (? t ? ? ) . Phasor representation of Voltage and Current The voltage and current waveforms are given as, v = 2 V sin ? and i = 2 I sin (? + ? ) It can be seen from the waveforms (Fig. 13. 2b) of the two sinusoidal quantities – voltage and current, that the voltage, V lags the current I, which means that the positive maximum value of the voltage is reached earlier by an angle, ? , as compared to the positive maximum value of the current. In phasor notation as described earlier, the voltage and current are represented by OP and OQ (Fig. 13. 2a) respectively, the length of which are proportional to voltage, V and current, I in different scales as applicable to each one. The voltage phasor, OP (V) lags the current phasor, OQ (I) by the angle ? , as two phasors rotate in the anticlockwise direction as stated earlier, whereas the angle ? is also measured in the anticlockwise direction. In other words, the current phasor (I) leads the voltage phasor (V). Version 2 EE IIT, Kharagpur Mathematically, the two phasors can be represented in polar form, with the voltage phasor ( V ) taken as reference, such as V = V ? 0 0 , and I = I . In Cartesian or rectangular form, these are, V = V ? 0 0 = V + j 0 , and I = I = I cos ? + j I sin ? , where, the symbol, j is given by j = ? . Of the two terms in each phasor, the first one is termed as real or its component in x-axis, while the second one is imaginary or its component in y-axis, as shown in Fig. 13. 3a. The angle, ? is in degree or rad. ? ? ? ? ? Phasor Algebra Before discussing the mathematical operations, like addition/subtraction and multiplication/division, involving phasors and also complex quantities, let us take a look at the two forms – polar and rectangular, by which a phasor or complex quantity is represented. It may be observed here that phasors are also taken as complex, as given above. You read "Applied Electricity Lecture Notes" in category "Essay examples" Representation of a phasor and Transformation A phasor or a complex quantity in rectangular form (Fig. 13. 3) is, A = ax + j a y Version 2 EE IIT, Kharagpur ? where a x and a y are real and imaginary parts, of the phasor respectively. In polar form, it is expressed as A = A a = A cos ? a + j A sin ? a ? where A and ? a are magnitude and phase angle of the phasor. From the two equations or expressions, the procedure or rule of transformation from polar to rectangular form is a x = A cos ? a and a y = A sin ? a From the above, the rule for transformation from rectangular to polar form is 2 2 A = a x + a y and ? = tan ? 1 (a y / a x ) The examples using numerical values are given at the end of this lesson. Addition/Subtraction of Phasors Before describing the rules of addition/subtraction of phasors or complex quantities, everyone should recall the rule of addition/subtraction of scalar quantities, which may be positive or signed (decimal/fraction or fraction with integer). It may be s tated that, for the two operations, the quantities must be either phasors, or complex. The example of phasor is voltage/current, and that of complex quantity is impedance/admittance, which will be explained in the next lesson. But one phasor and another complex quantity should not be used for addition/subtraction operation. For the operations, the two phasors or complex quantities must be expressed in rectangular form as A = a x + j a y ; B = bx + j b y If they are in polar form as A = A a ; B = B b In this case, two phasors are to be transformed to rectangular form by the procedure or rule given earlier. The rule of addition/subtraction operation is that both the real and imaginary parts have to be separately treated as ? ? ? ? where c x = (a x  ± b x ) ; c y = (a y  ± b y ) Say, for addition, real parts must be added, so also for imaginary parts. Same rule follows for subtraction. After the result is obtained in rectangular form, it can be transformed to polar one. It may be observed that the six values of a’ s , b’ s and c’ s – parts of the two phasors and the resultant one, are all signed scalar quantities, though in the example, a’ s and b’ s are taken as positive, resulting in positive values of c’ s . Also the phase angle ? ‘ s may lie in any of the four quadrants, though here the angles are in the first quadrant only. This rule for addition can be extended to three or more quantities, as will be illustrated through example, which is given at the end of this lesson. C = A  ± B = (a x  ± bx ) + j (a y  ± b y ) = c x + j c y ? ? ? Version 2 EE IIT, Kharagpur The addition/subtraction operations can also be performed using the quantities as ? ? ? phasors in polar form (Fig. 13. 4). The two phasors are A (OA) and B (OB) . The find the sum C (OC ) , a line AC is drawn equal and parallel to OB. The line BC is equal and parallel to OA. Thus, C = OC = OA + AC = OA + OB = A + B . Also, OC = OB + BC = OB + OA ? ? ? ? To obtain the difference D (OD) , a line AD is drawn equal and parallel to OB, but in opposite direction to AC or OB. A line OE is also drawn equal to OB, but in opposite direction to OB. Both AD and OE represent the phasor ( ? B ). The line, ED is equal to OA. Thus, D = OD = OA + AD = OA ? OB = A ? B . Also OD = OE + ED = ? OB + OA . The examples using numerical values are given at the end of this lesson. ? ? ? ? Multiplication/Division of Phasors Firstly, the procedure for multiplication is taken up. In this case no reference is being made to the rule involving scalar quantities, as everyone is familiar with them. Assuming that the two phasors are available in polar from as A = A a and B = B b . Otherwise, they are to be transformed from rectangular to polar form. This is also valid for the procedure of division. Please note that a phasor is to be multiplied by a complex quantity only, to obtain the resultant phasor. A phasor is not normally multiplied by another phasor, except in special case. Same is for division. A phasor is to be divided by a complex quantity only, to obtain the resultant phasor. A phasor is not normally divided by another phasor. ? ? ? To find the magnitude of the product C , the two magnitudes of the phasors are to be multiplied, whereas for phase angle, the phase angles are to added. Thus, Version 2 EE IIT, Kharagpur C = C c = A? B = A A ? B B = ( A ? B ) ? (? a + ? b ) ? ? ? where C = A ? B and ? c = ? a + ? b ? Please note that the same symbol, C is used for the product in this case. ? ? ? To divide A . by B to obtain the result D . , the magnitude is obtained by division of the magnitudes, and the phase is difference of the two phase angles. Thus, D = D d = ? ? A ? = B where D = A / B and ? d = ? a ? ? b ? ? A a ? A ? = ? ? ? (? a ? ? b ) B b ? B ? If the phasors are expressed in rectangular form as A = a x + j a y and B = bx + j by here A = (a 2 x ? 2 + a y ; ? a = tan ? 1 (a y / a x ) ) The values of B are not given as they can be obtained by substituting b’ s for a’ s . To find the product, C = C c = A ? B = (a x + j a y ) ? (bx + j b y ) = (a x bx ? a y b y ) + j (a x b y + a y bx ) ? ? ? Please note that j 2 = ? 1 . The magnitude and phase angle of the result (phasor) are, C = (a x bx ? a y b y ) + (a x b y + a y bx ) 2 [ 1 2 2 ] = (a 2 x 2 + ay ? ) (b 2 x 2 + b y = A ? B , and ) ? c = tan ? 1 ? ? ? a x b y + a y bx ? ? a x bx ? a y b y ? ? ? The phase angle, ? c = ? a + ? b = tan ? 1 ? ? a x b y + a y bx = tan ? 1 ? ?a b ? a b y y ? x x ? ? ? ? ay ? ax ? ? ? ? ? ? b ? + tan ? 1 ? y ? ?b ? ? x ? (a / a ) + (b y / bx ) ? ? ? = tan ? 1 ? y x ? ? ? 1 ? (a y / a x ) ? (b y / bx )? ? ? ? The above results are obtained by simplification. ? To divide A by B to obtain D as D = dx + j dy = ? ? A ? = ax + j a y bx + j by ? B To simplify D , i. e. to obtain real and imaginary parts, both numerator and denominator, are to be multiplied by the complex conjugate of B , so as to convert the ? denominator into real value only. The complex conjugate of B is Version 2 EE IIT, Kharagpur B * = bx + j b y = B ? ? ? b In the complex conjugate, the sign of the imaginary part is negative, and also the phase angle is negative. ? (a x + j a y )? (bx ? j by ) = ? a x bx + a y by ? + j ? a y bx ? a x by ? ? ? ? ? D = dx + j dy = (bx + j by )? (bx ? j by ) ? bx2 + by2 ? ? bx2 + by2 ? ? ? ? ? The magnitude and phase angle of the result (phasor) are, [(a b D= x x + a y b y ) + (a y bx ? a x b y ) 2 1 2 2 (b 2 x +b 2 y ) ] = (a (b 2 x 2 x 2 + ay 2 + by ) A = , and ) B ? a y bx ? a x b y ? ? ? d = tan ? 1 ? ?a b +a b ? y y ? ? x x The phase angle, ? ay ? ax ? ? ? ? tan ? 1 ? y ? b ? ? x ? ? a b ? a xby ? ? = tan ? 1 ? y x ? ?a b +a b y y ? ? x x ? ? ? ? ? d = ? a ? ? b = tan ? 1 ? ? The steps are shown here in brief, as detailed steps have been given earlier. Example ? The phasor, A in the rectangular form (Fig. 13. 5) is, A = A a = A cos ? a + j A sin ? a = a x + j a y = ? 2 + j 4 where the real and imaginary parts are a x = ? 2 ; ? ? ay = 4 To transform the phasor, A into the polar form, the magnitude and phase angle are Version 2 EE IIT, Kharagpur 2 2 A = a x + a y = (? 2) 2 + 4 2 = 4. 472 ? 4 ? ? = tan ? 1 ? ? ? 116. 565 ° = 2. 034 rad ? ? ? 2? ? Please note that ? a is in the second quadrant, as real part is negative and imaginary part is positive. ? a = tan ? 1 ? ? ? ay ? ax ? Transforming the phasor, A into rectangular form, the real and imaginary parts are a x = A cos? a = 4. 472 ? cos116. 565 ° = ? 2. 0 a y = A sin ? a = 4. 472 ? sin 116. 565 ° = 4. 0 Phasor Algebra ? ? ? Another phasor, B in rectangular form is introduced in addition to the earlier one, A B = 6 + j 6 = 8. 485 ? 45 ° Firstly, let us take the addition and subtraction of the above two phasors. The sum and ? difference are given by the phasors, C and D respectively (Fig. 13. 6). C = A+ B = (? 2 + j 4) +(6 + j 6) = (? 2 + 6) + j (4 + 6) = 4 + j 10 = 10. 77 ? 68. 2 ° D = A? B = (? 2 + j 4) ? (6 + j 6) = (? 2 ? 6) + j (4 ? 6) = ? 8 ? j 2 = 8. 246 ? ? 166. 0 ° It may be noted that for the addition and subtraction operations involving phasors, they should be represented in rectangular form as given above. If any one of the phasors Version 2 EE IIT, Kharagpur ? ? ? ? ? ? is in polar form, it should be transformed into rectangular form, for calculating the results as shown. If the two phasors are both in polar form, the phasor diagram (the diagram must be drawn to scale), or the geometrical method can be used as shown in Fig 13. 6. The result obtained using the diagram, as shown are the same as obtained earlier. [ C (OC) = 10. 77, ? COX = 68. 2 ° ; and D ( OD) = 8. 246, ? DOX = 166. 0 ° ] Now, the multiplication and division operations are performed, using the above two phasors represented in polar form. If any one of the phasors is in rectangular form, it may be transformed into polar form. Also note that the same symbols for the phasors are used here, as was used earlier. Later, the method of both multiplication and division using rectangular form of the phasor representation will be explained. ? ? ? The resultant phasor C , i. e. the product of the two phasors is C = A? B = 4. 472 ? 116. 565 ° ? 8. 485 ? 45 ° = (4. 472 ? 8. 485) ? (116. 565 ° + 45 °) = 37. 945 ? 161. 565 ° = ? 36 + j 12 The product of the two phasors in rectangular form can be found as C = (? 2 + j 4) ? (6 + j 6) = (? 12 ? 24) + j (24 ? 12) = ? 36 + j 12 ? ? ? ? ? ? ? The result ( D ) obtained by the division of A by B is D= ? ? A ? = B = 0. 167 + j 0. The above result can be calculated by the procedure described earlier, using the rectangular form of the two phasors as D= ? ? 4. 472 ? 116. 565 ° ? 4. 472 ? =? ? ? (116. 565 ° ? 45 °) = 0. 527 ? 71. 565 ° 8. 485 ? 45 ° ? 8. 485 ? A ? = B 12 + j 36 = = 0. 167 + j 0. 5 72 ? 2 + j 4 ( ? 2 + j 4) ? (6 ? j 6) (? 12 + 24) + j (24 + 12) = = 6+ j6 ( 6 + j 6) ? ( 6 ? j 6) 62 + 62 The procedure for the elementary operations using two phasors only, in both forms of representation is shown. It can be easily extended, for say, addition/multiplication, using three or more phasors. The simplification procedure with the scalar quantities, using the different elementary operations, which is well known, can be extended to the phasor quantities. This will be used in the study of ac circuits to be discussed in the following lessons. The background required, i. e. phasor representation of sinusoidal quantities (voltage/current), and algebra – mathematical operations, such as addition/subtraction and multiplication/division of phasors or complex quantities, including transformation of phasor from rectangular to polar form, and vice versa, has been discussed here. The study of ac circuits, starting from series ones, will be described in the next few lessons. Version 2 EE IIT, Kharagpur Problems 13. 1 Use plasor technique to evaluate the expression and then find the numerical value at t = 10 ms. i ( t ) = 150 cos (100t – 450 ) + 500 sin (100t ) + d ? cos 100t – 30 0 ) ? ? dt ? ( 13. 2 Find the result in both rectangular and polar forms, for the following, using complex quantities: 5 – j12 15 ? 53. 1 ° b) ( 5 – j12 ) +15 ? – 53. 1 ° a) 2 ? 30 ° – 4 ? 210 ° 5 ? 450 ° 1 ? ? d) ? 5 ? 0 ° + ? . 2 ? 210 ° 3 2 ? – 45 ° ? ? c) Version 2 EE IIT, Kharagpur List of Figures Fig. 13. 1 (a) Phasor representation of a sinusoidal voltage, and (b) Waveform Fig. 13. 2 (a) Phasor representation of voltage and current, and (b) Waveforms Fig. 13. 3 Representation of a phasor, both in rectangular and polar forms Fig. 13. 4 Addition and subtraction of two phasors, both represented in polar form Fig. 13. 5 Representation of phasor as an example, both in rectangular and polar forms Fig. 13. 6 Addition and subtraction of two phasors represented in polar form, as an example Version 2 EE IIT, Kharagpur How to cite Applied Electricity Lecture Notes, Essay examples

Deppression and teens Essay Example For Students

Deppression and teens Essay By: Shelby Manning E-mail: emailprotected Teenage depression is a growing problem in todays society and is often a major contributing factor for a multitude of adolescent problems. The statistics about teenage runaways, alcoholism, drug problems, pregnancy, eating disorders, and suicide are alarming. Even more startling are the individual stories behind these statistics because the young people involved come from all communities, all economic levels, all home situations-anyones family. The common link is often depression. For the individuals experiencing this crisis, the statistics become relatively meaningless. The difficult passage into adolescence and early adulthood can leave lasting scars on the lives and psyches of an entire generation of young men and women. There is growing realization that teenage depression can be life- changing, even life-threatening. (McCoy 21) Depression is a murky pool of feelings and actions scientists have been trying to understand since the days of Hippocrates, who called it a black bile. It has been called the common cold of mental illness and, like the cold, its difficult to quantify. (Arbetter 1) If feelings of great sadness or agitation last for much more than two weeks, it may be depression. For a long time, people who were feeling depressed were told to snap out of it. According to a study done by National Institute of Mental Health, half of all Americans still view depression as a personal weakness or character flaw. Depression, however, is considered a medical disorder and can affect thoughts, feelings, physical health, and behaviors. It interferes with daily life such as school, friends, and family. Clinical depression is the most incapacitating of all chronic conditions in terms of social functioning. (Salmans 11-12) Teenagers have always been vulnerable to depression for a variety of reasons. Its a confusing time of life because a teens body is changing along with their relationships. Teenagers constantly vacillate between strivings for independence from family and regressions to childish dependence on it. (Elkind 89) But todays teens face an additional challenge: Theyre growing up in a world quite different from that of their parents youth. Adolescents today are faced with stresses that were unknown to previous generations and are dealing with them in an often self-destructive way. Contemporary society has changed the perception of teenagers. New parental lifestyles, combined with changes in the economy, often give less time and energy for parents to devote to their offspring. Society all too often views teens for what they can be instead of for who they are. Who they are becomes the identity of teenagers today. They are confronted with the ambiguity of education, the dis! solution of family, the hostile commercialism of society, and the insecurity of relationships. (McCoy 16) This identity is fragile and is threatened by fears of rejection, feelings of failure, and of being different. These young people face stress in school as well with resources dwindling and campus violence and harassment increasing. Their sexual awakening comes in the age of AIDS, when sex can kill. In summary, teens today feel less safe, less empowered and less hopeful than we did a generation ago. Depression is a common concomitant to this struggle. (McCoy 36) It strikes 5% of teens and about 2% of children under 12. One in three adolescents in the nineties is at risk for serious depression. (Stern 28) Depression is the result of a complex mix of social, psychological, physical, and environmental factors. Teens with depressed parents are two to three times more likely to develop major depression. Genetic factors play a substantial but not overwhelming role in causing depression. (Dowling 37) Some type of significant loss can be a factor in triggering teenage depression. Loss can be due to death, divorce, separation, or loss of a family member, important friend or romantic interest. Loss can also be more subtle such as the loss of childhood, of a familiar way of being, of goals through achievement, or of boundaries and guidelines. (McCoy 46-48) Gender differences are becoming apparent, with girls having more difficulty with depression. Multiculturalism in Canada Essay (Elkind 203) Researchers have found that depressed teens are at particularly high risk for drug and alcohol abuse. Abuse of drugs, alcohol, or other substances are often used to assuage depression. Studies have found that when depressed patients were given treatment, alcohol and drug intake diminished as well. Substance abuse is seen as both a symptom and a cause of depression. (Papolos 66) There is more sexual activity among teenagers today than at any other time in our history. By the time they leave high school, some 90% of seniors are no longer virgins. Sexually transmitted diseases among teenagers have reached epidemic proportions. Eight million young people each year are infected with a sexually transmitted disease. Every thirty seconds, another U.S. teenager is infected. (Elkind 71) Sexual acting-out , which can not only be life-changing, but also life-threatening in this age of AIDS, can become an antidote to the loneliness and isolation many teenagers feel. Sexual activity is often used as an attempt to deal with feelings of depression, to increase self-esteem by feeling wanted and to achieve intimacy. (McCoy 21) Approximately 3,000 teenage girls in the United States will get pregnant today. An estimated 3 million teenage girls become pregnant each year. Beth is a shy, quiet eighth-grader who is expecting a baby in two months. Beth admits her pregnancy was intentional and she plans to keep her baby because then Ill have someone of my own who will love me for sure. I wont be alone anymore. This illusion of unconditional love, coupled with a lack of insight into the unrelenting demands that the complete dependence of an infant brings leads a number of girls to seek pregnancy. Some teens see parenthood as a way to recapture the joy of childhood they are losing, a way to be loved and important to someone else, or as an antidote to depression. (McCoy 81-82) Suicide among teenagers has skyrocketed 200% in the last decade. If we were talking about mononucleosis or meningitis wed call this an epidemic. (Solin 155) Suicide has become the second leading cause of death among older teenagers. Adolescents are particularly at risk for suicide attempts because they progress through a variety of rapid developmental stages. The seriously depressed teen may often have a sense of hopelessness. Many teens are too immobilized by depression to see any alternatives or to take any positive steps toward change. (Salmans 40) All too often depressed teenagers dont have the experience to know that time heals, that there is always hope. They dont realize that they can survive a crisis and perhaps even learn from it. Life is often seen in absolutes which intensifies any crisis. (McCoy 64) The destructive potential of serious teenage depression can have many long-lasting aftereffects. Having and keeping a baby, getting into trouble with the law, sustaining a serious injury as the result of risk-taking behavior or stunting ones emotional growth by anesthetizing painful feelings with drugs or alcohol can have a great impact on ones future. It can prevent a young adult from having a full, healthy, and productive life or make it considerably more difficult to do so. Depression is a growing problem amongst todays teenagers. Depression brings with it many problems that can be self-destructive. If a teenager has the benefit of early intervention and help in coping with his or her depression, however, the life script can be quite different. (McCoy 66-67) Word Count: 1856