The angle an airplane propeller makes with the horizontal as a function of time is given by θ = (125 rad/s)t + (42.5 rad/s2)t 2. (a) Estimate the instantaneous angular velocity at t = 0.00 s by calculating the average angular velocity from t = 0.00 s to t = 0.010 s. (b) Estimate the instantaneous angular velocity at t − 1.000 s by calculating the average angular velocity from t = 1.000 s to t = 1.010 s. (c) Estimate the instantaneous angular velocity at t = 2.000 s by calculating the average angular velocity from t = 2.000 s to t = 2.010 s. (d) Based on your results from parts (a), (b), and (c), is the angular acceleration of the propeller positive, negative, or zero? Explain. (e) Calculate the average angular acceleration from t = 0.00 s to t − 1.00 s and from t = 1.00 s to t = 2.00 s.
SECTION 10-2 ROTATIONAL KINEMATICS
The Cold War, I I. Origins A. Yalta: Identified as beginning of Cold War; Big 3 (Stalin, Roosevelt, and Churchill) met to discuss what they were going to do when the war ended. Stalin was in a place of power because the Soviet Union had already almost met its wartime goals, while Britain and the U.S. had fallen behind. Stalin wanted a buffer zone between Germany and the Soviet Union, and he wanted it to be proSoviet Union. Britain and the U.S. wanted democracy, and they wanted these new nations to have freely elected governments. Stalin knew no freely elected government would be proSoviet Union. a. It was agreed that the Soviet Union could take reparations from Germany. As they oved in, they started to take their reparations in industrial equipment, stripping away everything from Eastern Germany as they passed through. B. Potsdam (July 1945): New President Truman is very adamant about the Free Elections issue. Formulates the Doctrine of Containment. Argues that he will “Get tough” with the soviets and prevent the spread of communism. Tried to make other places less susceptible to communism. C. Truman Doctrine (1947): The doctrine created by Truman that was designed to make places less susceptible to communism. Started with Greece and Turkey. Gave a great deal of foreign aid. D. Marshal Plan: Truman had his secretary, George Marshal, announce the Marshal plan. The U.S. would give huge amounts of money (150 billion in today’s money) to 16 nations to help them recover from the war. Economic miracle; by 1951, all of the countries had almost fully recovered, only four years after the plan went into effect. E. Truman, in 1946, had Winston Churchill come to a small college in America and there, he gave the Iron Curtain speech, where he spoke about how the Soviet Union controlled all of Eastern Europe (which would last until 1989). The effect was powerful. Turned the tide in support for Truman’s policies. F. NATO: Alliance between America and most of Europe II. Cold War Conflicts A. Division of Berlin: Germany was split into East Germany (controlled by the soviets) and West Germany (controlled by the other Allies). Berlin was in East Germany, but was also split because it was the capital. West Germany recovered much faster than East Germany because it hadn’t been stripped of industrial equipment and had aid from the Allies. The people in East Germany could see that the Western area was recovered so much better and so they wanted to go there. B. Problem of Refugees: People started flooding from East to West Germany by getting into West Berlin and, from there, escaping to West Germany. C. Berlin Airlift (1949): In retaliation, the soviets closed off Berlin, sealing it off from everything. In reaction, Britain and the U.S. organized the Berlin Airlift. For 10 ½ months, they flew in planes from the outside with food and other basic materials. Western allies saved Berlin. Showed Berlin that the western allies were on their side. Allied victory without open military conflict. III. Korean War: In WWII, Korea was occupied by Japan. After the war, it was divided into zones of occupation. North Korea was controlled by the Soviet Union, while South Korea was controlled by America and her allies. Both halves wanted to be united again, but they hated each other and didn’t want the other to be the one that united them. A. For this reason, in 1950, North Korea invaded South Korea. Because North Korea was communist, America, along with other members of the United Nations, decided to get involved on the side of South Korea. th B. They pushed the Northerners out of South Korea, crossed the 38 parallel (the dividing line between North and South Korea), and made it almost to China. China had declared that if they crossed the 38 parallel, China would protect North Korea. MacArthur wanted to invade China, and was eventually fired for disobeying orders. The war became a stalemate until 1951, when there was an armistice and Korea was divided permanently. Cold War, II I. McCarthyism A. Idea of communist subversion: there was a feeling among the American people that there were communist spies inside the country who worked to destroy capitalism and the American way of life. a. Los Alamos: where the first atomic bomb was created. America had an advantage in the Cold War from 1945 to 1949, when the USSR developed their own atomic bomb. i. Fed McCarthyism because people were convinced that spies had turned over the secret to the atomic bomb, which was only made worse when people like Julius and Ethel Rosenburg admitted to that very thing and were executed. B. McCarthy’s speech: McCarthy gave a speech where he said that he had a list of 205 names of communist subversives in the state department that the government knew about but had done nothing to stop. Began the phenomenon of McCarthyism. Was a complete lie. C. Investigations: Anyone whose political views were too leftwardleaning (or liberal) were investigated, many over them losing their jobs and/or had their names dragged through the dirt. Included everyone from politicians to Hollywood directors. II. Changing Attitudes in the 1950s A. Russia (Soviet Union, USSR): became less aggressive a. European Recovery: many areas of Europe recovered economically, going from living in rubble to having producing economies. Easter Europe, however, was not recovering at nearly the same rate. b. U.S. willingness to fight in Korea: sent a message to the Soviet Union that the U.S. and her allies were more than willing to go to war to prevent the spread of communism. c. Food shortages: Eastern European countries under the control of the Soviet Union didn’t have enough food. d. Hold over Satellites weakens: still had control, but not to the same degree that they used to. B. U.S. a. Eisenhower elected: said he would be even harder on communism, but that’s not what happened. b. Hungary (1956): Soviet satellite; rose up, tried to overthrow soviet control. This had been the moment the allies had been waiting for, their opening to start the downfall of communism, but Eisenhower did nothing to aid the rebels, and the uprising was ruthlessly put down by the USSR. c. North Vietnam goes communist: again, America does nothing. d. Russia’s atomic bomb: everyone knew that a twosided nuclear war would mean annihilation. C. Relaxation: combined causes listed above resulted in a period that was characterized as “Peaceful coexistence”. III. Berlin Wall A. Over 3 million people had fled East Germany by making their way into West Berlin and, from there, into West Germany. B. August 1961: Communists put up a wall, first of barbed wire and slowly fortified until it was concrete and impassible. Blocked West Berlin from East Berlin. IV.Cuban Missile Crisis (October 1962) A. Castro: In 1959, Castro came to power as the result of a revolution where Batista was overthrown. Cuba was very poor, and Castro wanted to carry out a communist revolution to alleviate the poverty. Castro pursued closer relationships between Cuba and the Soviet Union. a. Cuba is only 90 miles from the U.S., so this was obviously a problem, having communism so close to our borders. b. Kennedy become president in 1961. Decided something needed to be done about this new communist problem. Attacked Cuba in the Bay of Pigs. Took 100 Cuban refugees, trained them, and sent them to the Bay of Pigs to attempt to overthrow the communist Cuban government. Failed pretty epically. c. October 1962: the U.S. learned the Soviet Union was setting up missile sites in Cuba. Kennedy set up a naval blockade around Cuba to turn back Soviet ships. Eventually the soviets backed off. V. Space Race A. Sputnik (1957): The first satellite sent into space; sent by the Soviet Union. Was alarming to the U.S., fast forwarded interest in space. B. Education: less than a month after Sputnik launched, the government decided that American education was not on par with the soviets’. They poured money into education, and there were huge curriculum changed so that public education reflected the state of modern science and math. Created a gap between children and their parents as the children were privy to such an extended education that many of their parents lacked. C. NASA: tried to step up the space race. Put together a team of 7 astronauts (the Mercury team) who were to be the first men in space, but they were beat to it by Yuri Gagarin, a soviet astronaut who orbited the earth on the first ever trip to space. Alan Shepherd was the first American to reach space, but it wasn’t until John Glenn that an American orbited the earth. Indian Nationalism I. British Rule A. India as a British colony: India was known as the “Jewel in the Crown”; very valuable to Britain. There were very few positive consequences on India, and a great amount of negative consequences, particularly involving poverty. B. Nationalism and World War I: India supported the British war effort. 900,000 Indians served in British armies. Many people that weren’t soldiers supported the war effort in other ways. WWI engendered nationalism. At first, India only wanted a part in their own government, but Britain shut their requests down. C. Famine and Epidemic: 19181919; global flu epidemic, closely associated with famine in many places, including India. D. Chelmsford Reforms: concessions made to Indian nationalistic wishes; gave over certain roles in government to Indians. Problem was that all roles given were not particularly important, further infuriating some Indians. E. Rawlatt Act: Clamped down on freedom of the press and gave British government the power to put Indians in jail because they might commit crimes, even if they hadn’t done anything yet. F. Amritsar Massacre: 1919; started as a nonviolent protest; British General Dyer ordered his men to fire into an unarmed crowd to break up the protest. Killed 400 Indians and injured 1200 more. British government rewarded General Dyer with knighthood, enraging the Indian population. II. Gandhi A. Early Life: Sent to Britain by his parents for schooling in law. There, he learned about Western political values. Came from a middle class family, and was deeply influenced by his mother, a very devout Hindu. B. Experience in South Africa: Gandhi’s first job as an attorney was in South Africa, where there was a sizeable Indian population. He worked as an attorney to service those people. Became an activist working to diminish the discrimination in the region. C. Nonviolent resistance: Gandhi becomes the leader of the resistance movement in India upon his return. Hindus hated violence, and Gandhi personally though violence was unnecessary for political upheavals. He wanted to take the moral high ground, and thought that far more could be accomplished that way. Emphasized getting right spiritually and particularly emphasized noncooperation. Wanted people to stop using the judicial system, paying taxes, really anything that involved the British government. Intentionally used protests to put many of his followers in jail, packing the facilities until there was no space for any more, breaking the system. D. March to the Sea (1930): British had a monopoly on the sale of salt, and it was heavily taxed. Gandhi led thousands in a 240 mile march to the sea to make their own salt. A very symbolic moment in the Indian nationalist movement that brought international attention to the movement. III. Indian National Congress: goal was to modernize India and to try to achieve a degree of self rule in India. A. Nehru: Gandhi protégée. Other face of Indian nationalism. Educated in England from a young age. Attorney like Gandhi, but not as spiritual. Very pragmatic, somewhat socialist; all about technology and modernizing. Led Indian National Congress. B. Muslim League: There was a sizeable Muslim minority in India led by Muhammad Ali Jinnah, and were represented in the Indian National Congress. Were afraid of Gandhi, and were afraid that if they succeeded in getting rid of the British, Gandhi would set up a Hindu state, and the Muslims would be treated poorly. IV.Partition (1947) A. After WWII, Britain could no longer afford to fight India. In 1945 they announced that they would begin the plans to give India their independence, and in 1947 they divided India into sections. The main body was left as India, a Hindu nation, but several areas where the Muslim population was particularly prominent were formed into Pakistan and Bangladesh.