Questões - AFA | Gabarito e resoluções

(AFA - 2014) SEPTEMBER 11 On September 11, 2001, nineteen militants associated with the Islamic extremist group al-Qaeda hijacked four airlines and carried out suicide attacks against targets in the United States. Two of the planes 5were flown into the towers of the World Trade Center in New York City, a third plane hit the Pentagon just outside Washington, D.C., and the fourth plane crashed in a field in Pennsylvania. Often referred to as 9/11, the attacks resulted in extensive death and destruction, activating 10major U.S. initiatives to combat terrorism and defining the presidency of George W. Bush. Over three thousand people were killed during the attacks in New York City and Washington, D.C., including more than four hundred police officers and firefighters. 15 At 8:45 a.m., on a clear Tuesday morning, an American Airlines Boeing 767 loaded with twenty thousand gallons of jet fuel crashed into the north tower of the World Trade Center in New York City. The impact left a wide, burning hole near the 80th floor of the 110- 20story skyscraper, instantly killing hundreds of people and trapping hundreds more in higher floors. Eighteen minutes after the first plane hit, a second Boeing 767 United Airlines Flight 175appeared out of the sky, turned sharply toward the World Trade Center and 25crashed into the south tower near the 60th floor. The collision caused a massive explosion that showered burning fragment over surrounding buildings and the streets below. America was under attack. The attackers were Islamic terrorists from Saudi 30Arabia and several other Arab nations. Reportedly financed by Saudi fugitive Osama bin Ladens al-Qaeda terrorist organization, they _____________(1) in retaliation for Americas support of Israel, its involvement in the Persian Gulf War and its continued military 35presence in the Middle East. Some of the terrorists had lived in the United States for more than a year and _____________(2) flying lessons at American commercial flight schools. As millions watched the events unfolding in New 40York, American Airlines Flight 77 circled over downtown Washington, D.C., and banged into the west side of the Pentagon military headquarters at 9:45 a.m. Jet fuel from the Boeing 757 caused a devastating inferno that led to the structural collapse of a portion of the giant concrete 45building. Less than fifteen minutes after the terrorists struck the nerve center of the U.S. military, the horror in New York took a catastrophic turn for the worse when the south tower of the World Trade Center collapsed in a massive cloud of dust and smoke. At 10:30 a.m., the 50other Trade Center tower collapsed. Close to three thousand people died in the World Trade Center and its vicinity, including an impressive three hundred and forty three firefighters and paramedics, twenty three New York City police officers and thirty seven Port Authority police 55officers who were struggling to complete an evacuation of the buildings and save the office workers trapped* on higher floors. Meanwhile, a fourth California-bound plane United Flight 93was hijacked about forty minutes after 60leaving Newark International Airport in New Jersey. Because the plane had been delayed in taking off, passengers on board learned of events in New York and Washington via cell phone calls to the ground. Knowing that the aircraft was not returning to an airport as the 65hijackers claimed, a group of passengers and flight attendants planned a rebellion. One of the passengers, Thomas Burnett Jr., told his wife over the phone that I know were all going to die. There are three of us who are going to do something about it. I love you, honey. 70Another passengerTodd Beamerwas heard saying Are you guys ready? Lets roll over an open line. The passengers fought the four hijackers and are suspected to have attacked the cockpit with a fire extinguisher. The plane then flipped over and sped 75toward the ground, crashing in a rural field in western Pennsylvania at 10:10 a.m. All forty-five people aboard were killed. Within two months, U.S. forces had effectively removed the Taliban from operational power, but the war continued. Osama bin Laden, was finally 80chased and killed by U.S. forces in Abbottabad, Pakistan. Adapted from http://www.history.com/topics/9-11-attacks Acessado em 04/04/2013 Glossary: *Trapped to be in a bad situation that is difficult to escape. The verb learned (line 62) has the same meaning as

(AFA - 2014) SEPTEMBER 11 On September 11, 2001, nineteen militants associated with the Islamic extremist group al-Qaeda hijacked four airlines and carried out suicide attacks against targets in the United States. Two of the planes 5were flown into the towers of the World Trade Center in New York City, a third plane hit the Pentagon just outside Washington, D.C., and the fourth plane crashed in a field in Pennsylvania. Often referred to as 9/11, the attacks resulted in extensive death and destruction, activating 10major U.S. initiatives to combat terrorism and defining the presidency of George W. Bush. Over three thousand people were killed during the attacks in New York City and Washington, D.C., including more than four hundred police officers and firefighters. 15 At 8:45 a.m., on a clear Tuesday morning, an American Airlines Boeing 767 loaded with twenty thousand gallons of jet fuel crashed into the north tower of the World Trade Center in New York City. The impact left a wide, burning hole near the 80th floor of the 110- 20story skyscraper, instantly killing hundreds of people and trapping hundreds more in higher floors. Eighteen minutes after the first plane hit, a second Boeing 767 United Airlines Flight 175appeared out of the sky, turned sharply toward the World Trade Center and 25crashed into the south tower near the 60th floor. The collision caused a massive explosion that showered burning fragment over surrounding buildings and the streets below. America was under attack. The attackers were Islamic terrorists from Saudi 30Arabia and several other Arab nations. Reportedly financed by Saudi fugitive Osama bin Ladens al-Qaeda terrorist organization, they _____________(1) in retaliation for Americas support of Israel, its involvement in the Persian Gulf War and its continued military 35presence in the Middle East. Some of the terrorists had lived in the United States for more than a year and _____________(2) flying lessons at American commercial flight schools. As millions watched the events unfolding in New 40York, American Airlines Flight 77 circled over downtown Washington, D.C., and banged into the west side of the Pentagon military headquarters at 9:45 a.m. Jet fuel from the Boeing 757 caused a devastating inferno that led to the structural collapse of a portion of the giant concrete 45building. Less than fifteen minutes after the terrorists struck the nerve center of the U.S. military, the horror in New York took a catastrophic turn for the worse when the south tower of the World Trade Center collapsed in a massive cloud of dust and smoke. At 10:30 a.m., the 50other Trade Center tower collapsed. Close to three thousand people died in the World Trade Center and its vicinity, including an impressive three hundred and forty three firefighters and paramedics, twenty three New York City police officers and thirty seven Port Authority police 55officers who were struggling to complete an evacuation of the buildings and save the office workers trapped* on higher floors. Meanwhile, a fourth California-bound plane United Flight 93was hijacked about forty minutes after 60leaving Newark International Airport in New Jersey. Because the plane had been delayed in taking off, passengers on board learned of events in New York and Washington via cell phone calls to the ground. Knowing that the aircraft was not returning to an airport as the 65hijackers claimed, a group of passengers and flight attendants planned a rebellion. One of the passengers, Thomas Burnett Jr., told his wife over the phone that I know were all going to die. There are three of us who are going to do something about it. I love you, honey. 70Another passengerTodd Beamerwas heard saying Are you guys ready? Lets roll over an open line. The passengers fought the four hijackers and are suspected to have attacked the cockpit with a fire extinguisher. The plane then flipped over and sped 75toward the ground, crashing in a rural field in western Pennsylvania at 10:10 a.m. All forty-five people aboard were killed. Within two months, U.S. forces had effectively removed the Taliban from operational power, but the war continued. Osama bin Laden, was finally 80chased and killed by U.S. forces in Abbottabad, Pakistan. Adapted from http://www.history.com/topics/9-11-attacks Acessado em 04/04/2013 Glossary: *Trapped to be in a bad situation that is difficult to escape. The sentence Thomas Burnett Jr. told his wife over the phone that I know that were all going to die is similar in meaning to Thomas Burnett Jr.

(AFA - 2014) SEPTEMBER 11 On September 11, 2001, nineteen militants associated with the Islamic extremist group al-Qaeda hijacked four airlines and carried out suicide attacks against targets in the United States. Two of the planes 5were flown into the towers of the World Trade Center in New York City, a third plane hit the Pentagon just outside Washington, D.C., and the fourth plane crashed in a field in Pennsylvania. Often referred to as 9/11, the attacks resulted in extensive death and destruction, activating 10major U.S. initiatives to combat terrorism and defining the presidency of George W. Bush. Over three thousand people were killed during the attacks in New York City and Washington, D.C., including more than four hundred police officers and firefighters. 15 At 8:45 a.m., on a clear Tuesday morning, an American Airlines Boeing 767 loaded with twenty thousand gallons of jet fuel crashed into the north tower of the World Trade Center in New York City. The impact left a wide, burning hole near the 80th floor of the 110- 20story skyscraper, instantly killing hundreds of people and trapping hundreds more in higher floors. Eighteen minutes after the first plane hit, a second Boeing 767 United Airlines Flight 175appeared out of the sky, turned sharply toward the World Trade Center and 25crashed into the south tower near the 60th floor. The collision caused a massive explosion that showered burning fragment over surrounding buildings and the streets below. America was under attack. The attackers were Islamic terrorists from Saudi 30Arabia and several other Arab nations. Reportedly financed by Saudi fugitive Osama bin Ladens al-Qaeda terrorist organization, they _____________(1) in retaliation for Americas support of Israel, its involvement in the Persian Gulf War and its continued military 35presence in the Middle East. Some of the terrorists had lived in the United States for more than a year and _____________(2) flying lessons at American commercial flight schools. As millions watched the events unfolding in New 40York, American Airlines Flight 77 circled over downtown Washington, D.C., and banged into the west side of the Pentagon military headquarters at 9:45 a.m. Jet fuel from the Boeing 757 caused a devastating inferno that led to the structural collapse of a portion of the giant concrete 45building. Less than fifteen minutes after the terrorists struck the nerve center of the U.S. military, the horror in New York took a catastrophic turn for the worse when the south tower of the World Trade Center collapsed in a massive cloud of dust and smoke. At 10:30 a.m., the 50other Trade Center tower collapsed. Close to three thousand people died in the World Trade Center and its vicinity, including an impressive three hundred and forty three firefighters and paramedics, twenty three New York City police officers and thirty seven Port Authority police 55officers who were struggling to complete an evacuation of the buildings and save the office workers trapped* on higher floors. Meanwhile, a fourth California-bound plane United Flight 93was hijacked about forty minutes after 60leaving Newark International Airport in New Jersey. Because the plane had been delayed in taking off, passengers on board learned of events in New York and Washington via cell phone calls to the ground. Knowing that the aircraft was not returning to an airport as the 65hijackers claimed, a group of passengers and flight attendants planned a rebellion. One of the passengers, Thomas Burnett Jr., told his wife over the phone that I know were all going to die. There are three of us who are going to do something about it. I love you, honey. 70Another passengerTodd Beamerwas heard saying Are you guys ready? Lets roll over an open line. The passengers fought the four hijackers and are suspected to have attacked the cockpit with a fire extinguisher. The plane then flipped over and sped 75toward the ground, crashing in a rural field in western Pennsylvania at 10:10 a.m. All forty-five people aboard were killed. Within two months, U.S. forces had effectively removed the Taliban from operational power, but the war continued. Osama bin Laden, was finally 80chased and killed by U.S. forces in Abbottabad, Pakistan. Adapted from http://www.history.com/topics/9-11-attacks Acessado em 04/04/2013 Glossary: *Trapped to be in a bad situation that is difficult to escape. Mark the right option to complete the statement. If the plane hadnt been delayed in taking off, the passengers __________ about the events in New York and Washington.

(AFA - 2014) Um motociclista, pilotando sua motocicleta, move-se com velocidade constante durante a realizao do looping da figura abaixo. A Quando est passando pelo ponto mais alto dessa trajetria circular, o motociclista lana, para trs, um objeto de massa desprezvel, comparada massa de todo o conjunto motocicleta-motociclista. Dessa forma, o objeto cai, em relao superfcie da Terra, como se tivesse sido abandonado em A, percorrendo uma trajetria retilnea at B. Ao passar, aps esse lanamento, em B, o motociclista consegue recuperar o objeto imediatamente antes dele tocar o solo. Desprezando a resistncia do ar e as dimenses do conjunto motocicleta-motociclista, e considerando , a razo entre a normal (N), que age sobre a motocicleta no instante em que passa no ponto A, e o peso (P) do conjunto motocicleta-motociclista, (N/P), ser igual a

(AFA - 2014) Um bloco, de massa 2 kg, desliza sobre um plano inclinado, conforme a figura seguinte. O grfico vxt abaixo representa a velocidade desse bloco em funo do tempo, durante sua subida, desde o ponto A at o ponto B. Considere a existncia de atrito entre o bloco e o plano inclinado e despreze quaisquer outras formas de resistncia ao movimento. Sabendo que o bloco retorna ao ponto A, a velocidade com que ele passa por esse ponto, na descida, em m s, vale g = 10m/s; sen37= 0,6; cos37 = 0,8

(AFA - 2014) A figura abaixo mostra um sistema em equilbrio esttico, formado por uma barra homognea e uma mola ideal que esto ligadas atravs de uma de suas extremidades e livremente articuladas s paredes. A barra possui massa m e comprimento L0 , a mola possui comprimento natural L0 e a distncia entre as articulaes de 2L0. Esse sistema (barra-mola) est sujeito ao da gravidade, cujo mdulo da acelerao g e, nessas condies, a constante elstica da mola vale

(AFA - 2014) Dispe-se de duas mquinas trmicas de Carnot. A mquina 1trabalha entre as temperaturas de 227oCe 527oC,enquanto a mquina 2 opera entre 227 Ke 527 K. Analise as afirmativas a seguir e responda ao que se pede. I. A mquina 2 tem maior rendimento que a mquina 1. II. Se a mquina 1 realizar um trabalho de 2000 Jter retirado 6000 Jde calor da fonte quente. III. Se a mquina 2 retirar 4000 Jde calor da fonte quente ir liberar aproximadamente 1720 Jde calor para a fonte fria. IV. Para uma mesma quantidade de calor retirada da fonte quente pelas duas mquinas, a mquina 2 rejeita mais calor para a fonte fria. So corretas apenas

(AFA - 2014) Um corpo homogneo e macio de massa M e coeficiente de dilatao volumtrica constante imerso inicialmente em um lquido tambm homogneo temperatura de 0 C, e equilibrado por uma massa m1 atravs de uma balana hidrosttica, como mostra a figura abaixo. Levando o sistema formado pelo corpo imerso e o lquido at uma nova temperatura de equilbrio trmico x, a nova condio de equilbrio da balana hidrosttica atingida com uma massa igual a m2, na ausncia de quaisquer resistncias. Nessas condies, o coeficiente de dilatao volumtrica real do lquido pode ser determinado por

(AFA - 2014)Um estudante, ao repetir a experincia de James P. Joule para a determinao do equivalente mecnico do calor, fez a montagem da figura abaixo. Para conseguir o seu objetivo, ele deixou os corpos de massas M1 = 6,0 kg e M2 = 4,0 kg carem 40 vezes com velocidade constante de uma altura de 2,0 m, girando as ps e aquecendo 1,0 kg de gua contida no recipiente adiabtico. Admitindo que toda a variao de energia mecnica ocorrida durante as quedas dos corpos produza aquecimento da gua, que os fios e as polias sejam ideais e que o calor especfico da gua seja igual a 4,0 J/go C, o aumento de temperatura dela, em oC, foi de

(AFA - 2014) Considere um gs ideal que pode ser submetido a duas transformaes cclicas reversveis e no simultneas, 1 e 2,como mostrado no diagrama PV abaixo. Na transformao 1 o gs recebe uma quantidade de calor Q1 de uma fonte quente temperatura T1 e cede a quantidade de calor Q2 para a fonte fria temperatura T2.Enquanto que, na transformao 2, as quantidades de calor recebida, Q1, e cedida, Q2,so trocadas respectivamente com duas fontes s temperaturas T3e T4. Nessas condies, correto afirmar que

(AFA - 2014)A figura abaixo apresenta os grficos da posio (x) em funo do tempo (t) para dois sistemas A e B de mesma massa m que oscilam em MHS, de igual amplitude. Sendo ECA e ECB as energias cinticas dos sistemas A e B respectivamente no tempo t1: EPA e EPB as energias potenciais dos sistemas A e B respectivamente no tempo t2 , correto afirmar que

(AFA - 2014)Um pequeno objeto plano e luminoso pode ser utilizado em trs arranjospticos distintos (I, II e III), imersos em ar, como apresentado na figura abaixo. No arranjo I, o objeto colocado sobre um plano onde se apoiam dois espelhos planosortogonais entre si. Nos arranjos II e III, respectivamente, o objeto disposto de formaperpendicular ao eixo ptico de um espelho esfrico cncavo gaussiano e de uma lenteconvergente delgada. Dessa maneira, o plano do objeto se encontra paralelo aos planos focaisdesses dois dispositivos. Considere que as distncias do objeto ao vrtice do espelho esfricoe ao centro ptico da lente sejam maiores do que as distncias focais do espelho cncavo e dalente. Nessas condies, das imagens abaixo, a que no pode ser conjugada por nenhum dos trsarranjos pticos

(AFA - 2014) Um estudante montou um experimento com uma rede de difrao de 1000 linhas por milmetro, um laser que emite um feixe cilndrico de luz monocromtica de comprimento de onda igual a 4107m e um anteparo, conforme figura abaixo. O espectro de difrao, observado no anteparo pelo estudante, foi registrado por uma cmera digital e os picos de intensidade apareceram como pequenos pontos brilhantes na imagem. Nessas condies, a opo que melhor representa a imagem do espectro de difrao obtida pelo estudante :

(AFA - 2014) Trs cargas eltricas puntiformes qA, qB e qC esto fixas, respectivamente, nos vrtices A, B e C de um tringulo issceles, conforme indica a figura abaixo. Considerando FA o mdulo da fora eltrica de interao entre as cargas qA e qC; FB o mdulo da fora eltrica de interao entre as cargas qB e qC e sabendo-se que a fora resultante sobre a carga qC perpendicular ao lado AB e aponta para dentro do tringulo, pode-se afirmar, certamente, que a relao entre os valores das cargas eltricas

(AFA - 2014)Uma partcula A, de massa m e carga eltrica q, est em repouso no momento em que uma segunda partcula B, de massa e carga eltrica iguais s de A, lanada com velocidade de mdulo igual a v0, na direo x, conforme ilustra a figura abaixo. A partcula B foi lanada de um ponto muito distante de A, de tal forma que, no instante do lanamento, as foras eltricas coulombianas entre elas possam ser desprezadas. Sendo K a constante eletrosttica do meio e considerando apenas interaes eletrostticas entre essas partculas, a distncia mnima entre A e B ser igual a