Questões - AFA | Gabarito e resoluções

(AFA - 2009) Considere dois pssaros A e B em repouso sobre um fio homogneo de densidade linear , que se encontra tensionado, como mostra a figura abaixo. Suponha que a extremidade do fio que no aparece esteja muito distante da situao apresentada. Subitamente o pssaro A faz um movimento para alar vo, emitindo um pulso que percorre o fio e atinge o pssaro B t segundos depois. Despreze os efeitos que o peso dos pssaros possa exercer sobre o fio. O valor da fora tensora para que o pulso retorne posio onde se encontrava o pssaro A, em um tempo igual a 3t,

(AFA - 2009) Americans are well-known for being friendly. If weretaking a walk in the park and we pass someone, we usually say a few words to people in stores, bars and banks. But remember: friendliness is not friendship; its [5] politeness. In the United States, its just as hard to make real [6] friends as it is anywhere else. ( Move Up - Heinemann ) The sentence, In the United States its just hard to make real friends as it is anywhere else (lines 5 and 6), means

(AFA - 2009) Um par de blocos A e B, de massas mA= 2 kg e mB= 10 kg, apoiados em um plano sem atrito, acoplado a duas molas ideais de mesma constante elstica K = 50 N/m, como mostra a figura abaixo. Afastando-se horizontalmente o par de blocos de sua posio de equilbrio, o sistema passa a oscilar em movimento harmnico simples com energia mecnica igual a 50 J. Considerando g = 10 m/s2, o mnimo coeficiente de atrito esttico que deve existir entre os dois blocos para que o bloco A no escorregue sobre o bloco B

QUESTO ANULADA!! (AFA - 2009) Read the following opinions from two children, Chelsea and Eryn (both aged 8) and then answer questions 20 and 21 related to them. Is there future for us? Chelsea: The biggest problem with the environment is the ozone layer theres a hole, and its getting bigger. Its made by cars and airplanes things which give off fumes. Eryn: The ozone layers like a piece of paper covering a rock. Its supposed to protect us. Im scared the hole will get bigger and move around the world and people will get cancer. Chelsea: We could get tandems, and longer bikes, so children could ride on the back. Cars should be very, very expensive. Eryn: You also get bad pollution from burning down the rainforest. We should give money to poor people in Africa and places. Chelsea: We should spread out the people evenly. We could say, Put your hands up all those who want to live in Africa. And then wecould spread out the food. Theres enough to go around. Eryn: We use up far more of the earth than people in Africa so its a good idea for the whole world to discuss the environment. (Move up Heinemann) Both Chelsea and Eryn think that we should a)not to burn a lot of fuel. b)let poor people spread out the food. c)burn down rain forests. d) clean rivers and farmlands. QUESTO ANULADA!!

(AFA - 2009) Os valores do potencial eltrico V em cada vrtice de um quadrado esto indicados na figura abaixo. VA= 0 VB= VD= 5V VC= 10 V Os valores desses potenciais condizem com o fato de o quadrado estar situado num campo eletrosttico

(AFA - 2009) Na figura abaixo, uma partcula com carga eltrica positiva q e massa m lanada obliquamente de uma superfcie plana, com velocidade inicial de mdulo v0, no vcuo, inclinada de um ngulo em relao horizontal. Considere que, alm do campo gravitacional de intensidade g, atua tambm um campo eltrico uniforme de mdulo E. Pode-se afirmar que a partcula voltar altura inicial de lanamento aps percorrer, horizontalmente, uma distncia igual a

(AFA - 2009) Read the following opinions from two children, Chelsea and Eryn (both aged 8) and then answer questions 20 and 21 related to them. Is there future for us? Chelsea: The biggest problem with the environment is the ozone layer theres a hole, and its getting bigger. Its made by cars and airplanes things which give off fumes. Eryn: The ozone layers like a piece of paper covering a rock. Its supposed to protect us. Im scared the hole will get bigger and move around the world and people will get cancer. Chelsea: We could get tandems, and longer bikes, so children could ride on the back. Cars should be very, very expensive. Eryn: You also get bad pollution from burning down the rainforest. We should give money to poor people in Africa and places. Chelsea: We should spread out the people evenly. We could say, Put your hands up all those who want to live in Africa. And then wecould spread out the food. Theres enough to go around. Eryn: We use up far more of the earth than people in Africa so its a good idea for the whole world to discuss the environment. (Move up Heinemann) Chelsea and Eryn want to show us that in the future

(AFA - 2009) O elemento de aquecimento de uma torneira eltrica constitudo de dois resistores e de uma chave C, conforme ilustra a figura abaixo. Com a chave C aberta, a temperatura da gua na sada da torneira aumenta em 10 C. Mantendo-se a mesma vazo dgua e fechando C, pode-se afirmar que a elevao de temperatura da gua, em graus Celsius, ser de

(AFA - 2009) The Reluctant Learner My friend Tom is one of those six-to-midnight, enthusiastic, determined, and well-mentioned studiers. At six oclock he approaches his desk, and carefully organizes everything in preparation for the study period to follow. Having everything in place, he next carefully adjusts each item again, giving him [6] time to think up the first excuse; he recalls that in the [7] morning he did not have quite enough time to read all the [8] items of interest in the newspaper. He also realizes distractions completely out of the way before setting down to the task at hand. (Skyline 5 Macmillan) The sentence, ... he recalls that in the morning he did not have quite enough time to read all the items of interest in the newspaper (lines 6, 7 and 8) shows us how Tom

(AFA - 2009) The Reluctant Learner My friend Tom is one of those six-to-midnight, enthusiastic, determined, and well-mentioned studiers. At six oclock he approaches his desk, and carefully organizes everything in preparation for the study period to follow. Having everything in place, he next carefully adjusts each item again, giving him time to think up the first excuse; he recalls that in themorning he did not have quite enough time to read all the [8] items of interest in the newspaper. He also realizes [9] distractions completely out of the way before setting down to the task at hand. [10] (Skyline 5 Macmillan) He also realizes that if he is going to study it is better to have such distractions completely out of the way before setting down to the taskat hand. (lines 8, 9 and 10) The underlined word can be replaced by

(AFA - 2009) Parte de um circuito eltrico constituda por seis resistores hmicos cujas resistncias eltricas esto indicadas ao lado de cada resistor, na figura abaixo. Se a d.d.p. entre os pontos A e B igual a U, pode-se afirmar que a potncia dissipada pelo resistor R3 igual a

(AFA - 2009) Read the following paragraph and then answer questions 24 and 25 according to it. The Kremlin hoping a young strongman can preserve its brutal victory in Chechnya. (Newsweek, September, 2006) The underlined verbs is a (an)

QUESTO ANULADA!! (AFA - 2009) Uma bateria de f.e.m. igual a e resistncia interna de valor igual a r (constante) alimenta o circuito formado por uma lmpada L e um reostato R, conforme ilustra a figura abaixo. Considerando constante a resistncia da lmpada, o grfico que melhor representa a potncia por ela dissipada quando o cursor do reostato move-se de A para B a) b) c) d) QUESTO ANULADA!!

(AFA - 2009) O trecho AB, de comprimento 30 cm, do circuito eltrico abaixo, est imerso num campo magntico uniforme de intensidade 4 T e direo perpendicular ao plano da folha. Quando a chave CH fechada e o capacitor completamente carregado, atua sobre o trecho AB uma fora magntica de intensidade 3 N, deformando-o, conforme a figura. Sabe-se que os fios so ideais. A intensidade da corrente eltrica, em ampres, e a diferena de potencial eltrico entre os pontos C e D, em volts, so, respectivamente

QUESTO ANULADA!! (AFA - 2009) Read the following paragraph and then answer questions 24 and 25 according to it. The Kremlin hoping a young strongman can preserve its brutal victory in Chechnya. (Newsweek, September, 2006) Mark the alternative that completes the blanks of the statement below. The word its is a (an) pronoun and refers to . a)personal / young strong man. b)reflexive / Chechnya c)possessive adjective / The Kremlin hoping d)objective / victory QUESTO ANULADA!!  SHAPE  \* MERGEFORMAT