Foram encontradas 100 questões.
Considere quatro séries de experimentos em que quatro espécies químicas (X, Y, Z e W) reagem entre si, à pressão e temperatura constantes. Em cada série, fixam-se as concentrações de três espécies e varia-se a concentração !$ (C_0) !$ da quarta. Para cada série, determina- se a velocidade inicial da reação !$ (v_0) !$ em cada experimento. Os resultados de cada série são apresentados na figura, indicados pelas curvas X, Y, Z e W, respectivamente. Com base nas informações fornecidas, assinale a opção que apresenta o valor CORRETO da ordem global da reação química.
Provas
Questão presente nas seguintes provas
A questão refere-se ao texto abaixo:
DREAM ON, AMERICA
THE U.S. MODEL: For years, much of the world did aspire to the American way of life. But today countries are finding more appealing systems in their own backyards.
BY ANDREW MORAVCSIK
NOT LONG AGO, THE AMERICAN DREAM WAS a global fantasy. Not only Americans saw themselves as a beacon unto nations. So did much of the world.
(...)
You had only to listen to George W. Bush's Inaugural Address last week (invoking "freedom" and "liberty" 49 times) to appreciate just how deeply Americans still believe in this founding myth. For many in the world, the president's rhetoric confirmed their worst fears of an imperial America relentlessly pursuing its narrow national interests. But the greater danger may be a delusional America – one that believes, despite all evidence to the contrary, that the American Dream lives on, that America remains a model for the world, one whose mission is to spread the word.
The gulf between how Americans view themselves and how the world views them was summed up in a poll last week by the BBC. Fully 71 percent of Americans see the United States as a source of good in the world. More than half view Bush's election as positive for global security. Other studies report that 70 percent have faith in their domestic institutions and nearly 80 percent believe "American ideas and customs" should spread globally.
FOREIGNERS TAKE AN ENTIRELY different view: 58 percent in the BBC poll see Bush's reelection as a threat to world peace. Among America's traditional allies, the figure is strikingly higher: 77 percent in Germany, 64 percent in Britain and 82 percent in Turkey. Among the 1.3 billion members of the Islamic world, public support for the United States is measured in single digits. Only Poland, the Philippines and India viewed Bush's second Inaugural positively.
Tellingly, the anti-Bushism of the president's first term is giving way to a more general anti- Americanism. A plurality of voters (the average is 70 percent) in each of the 21 countries surveyed by the BBC oppose sending any troops to Iraq, including those in most of the countries that have done so. Only one third, disproportionately in the poorest and most dictatorial countries, would like to see American values spread in their country. Says Doug Miller of GlobeScan, which conducted the BBC report: "President Bush has further isolated America from the world. Unless the administration changes its approach, it will continue to erode America's good name, and hence its ability to effectively influence world affairs."
(...)
The truth is that Americans are living in a dream world. Not only do others not share America's selfregard, they no longer aspire to emulate the country's social and economic achievements. The loss of faith in the American Dream goes beyond this swaggering administration and its war in Iraq. A President Kerry ......(.1.6.)....s..imilar disaffection, for it grows from the success of something America holds dear: the spread of democracy, free markets and international institutions – globalization, in a word.
Countries today have dozens of political, economic and social models to choose from. Anti- Americanism is especially virulent in Europe and
Latin America, where countries have established their own distinctive ways - none made in America. Futurologist Jeremy Rifkin, in his recent book "The European Dream", hails an emerging European Union based on generous social welfare, cultural diversity and respect for international law – a model that's caught on quickly across the former nations of Eastern Europe and the Baltics. In Asia, the rise of autocratic capitalism in China or Singapore is as much a "model" for development as America's scandal-ridden corporate culture.
(...)
Many are tempted to write off the new anti- Americanism as a temporary perturbation, or mere resentment. Blinded by its own myth, America has grown incapable of recognizing its flaws. For there is much about the American Dream to fault. If the rest of the world has lost faith in the American model – political, economic, diplomatic – it's partly for the very good reason that it doesn't work as well anymore.
MORAVCSIK teaches politics and directs the European Union Program at Princeton University.
Newsweek, January 31, 2005, Páginas 17-19
Considere as afirmações:
I. O texto faz referência ao discurso de posse do presidente Americano George W. Bush.
II. No mundo islâmico em geral, a aprovação às políticas americanas não chega a 10%.
III.A maioria dos americanos empenha-se para que os Estados Unidos continuem sendo um modelo para o resto do mundo.
Então, está(ão) de acordo com o texto
Provas
Questão presente nas seguintes provas
Seja U um conjunto não vazio com n elementos, !$ n \ge 1 !$.
Seja S um subconjunto de P(U) com a seguinte propriedade:
Se !$ A !$, !$ B !$ !$ ∈ !$ !$ S !$, então !$ A !$ !$ ⊂ !$ !$ B !$ ou !$ B !$ !$ ⊂ !$ !$ A !$.
Então, o número máximo de elementos que !$ S !$ pode ter é
Provas
Questão presente nas seguintes provas
A ficção contemporânea brasileira é marcada por uma diversidade muito grande de temas e de estilos. Nesse universo ficcional, um dos escritores de maior singularidade é Murilo Rubião, autor de livros, como O pirotécnico Zacarias, O convidado e A casa do girassol vermelho, publicados nos anos 1970. Das opções abaixo, assinale a que melhor define a obra desse autor.
Provas
Questão presente nas seguintes provas
Seja E um ponto externo a uma circunferência. Os segmentos !$ \overline{EA} !$ e !$ \overline{ED} !$ interceptam essa circunferência nos pontos B e A, e, C e D, respectivamente. A corda !$ \overline{AF} !$ da circunferência intercepta o segmento !$ \overline{ED} !$ no ponto G. Se EB = 5, BA = 7, EC = 4, GD = 3 e AG = 6, então GF vale
Provas
Questão presente nas seguintes provas
A questão refere-se ao texto abaixo:
DREAM ON, AMERICA
THE U.S. MODEL: For years, much of the world did aspire to the American way of life. But today countries are finding more appealing systems in their own backyards.
BY ANDREW MORAVCSIK
NOT LONG AGO, THE AMERICAN DREAM WAS a global fantasy. Not only Americans saw themselves as a beacon unto nations. So did much of the world.
(...)
You had only to listen to George W. Bush's Inaugural Address last week (invoking "freedom" and "liberty" 49 times) to appreciate just how deeply Americans still believe in this founding myth. For many in the world, the president's rhetoric confirmed their worst fears of an imperial America relentlessly pursuing its narrow national interests. But the greater danger may be a delusional America – one that believes, despite all evidence to the contrary, that the American Dream lives on, that America remains a model for the world, one whose mission is to spread the word.
The gulf between how Americans view themselves and how the world views them was summed up in a poll last week by the BBC. Fully 71 percent of Americans see the United States as a source of good in the world. More than half view Bush's election as positive for global security. Other studies report that 70 percent have faith in their domestic institutions and nearly 80 percent believe "American ideas and customs" should spread globally.
FOREIGNERS TAKE AN ENTIRELY different view: 58 percent in the BBC poll see Bush's reelection as a threat to world peace. Among America's traditional allies, the figure is strikingly higher: 77 percent in Germany, 64 percent in Britain and 82 percent in Turkey. Among the 1.3 billion members of the Islamic world, public support for the United States is measured in single digits. Only Poland, the Philippines and India viewed Bush's second Inaugural positively.
Tellingly, the anti-Bushism of the president's first term is giving way to a more general anti- Americanism. A plurality of voters (the average is 70 percent) in each of the 21 countries surveyed by the BBC oppose sending any troops to Iraq, including those in most of the countries that have done so. Only one third, disproportionately in the poorest and most dictatorial countries, would like to see American values spread in their country. Says Doug Miller of GlobeScan, which conducted the BBC report: "President Bush has further isolated America from the world. Unless the administration changes its approach, it will continue to erode America's good name, and hence its ability to effectively influence world affairs."
(...)
The truth is that Americans are living in a dream world. Not only do others not share America's selfregard, they no longer aspire to emulate the country's social and economic achievements. The loss of faith in the American Dream goes beyond this swaggering administration and its war in Iraq. A President Kerry ......(.1.6.)....s..imilar disaffection, for it grows from the success of something America holds dear: the spread of democracy, free markets and international institutions – globalization, in a word.
Countries today have dozens of political, economic and social models to choose from. Anti- Americanism is especially virulent in Europe and
Latin America, where countries have established their own distinctive ways - none made in America. Futurologist Jeremy Rifkin, in his recent book "The European Dream", hails an emerging European Union based on generous social welfare, cultural diversity and respect for international law – a model that's caught on quickly across the former nations of Eastern Europe and the Baltics. In Asia, the rise of autocratic capitalism in China or Singapore is as much a "model" for development as America's scandal-ridden corporate culture.
(...)
Many are tempted to write off the new anti- Americanism as a temporary perturbation, or mere resentment. Blinded by its own myth, America has grown incapable of recognizing its flaws. For there is much about the American Dream to fault. If the rest of the world has lost faith in the American model – political, economic, diplomatic – it's partly for the very good reason that it doesn't work as well anymore.
MORAVCSIK teaches politics and directs the European Union Program at Princeton University.
Newsweek, January 31, 2005, Páginas 17-19
A expressão to give way to destacada no texto, é equivalente a
Provas
Questão presente nas seguintes provas
Uma haste metálica de comprimento 20,0 cm está situada num plano xy, formando um ângulo de 30° com relação ao eixo Ox. A haste movimenta-se com velocidade de 5,0 m/s na direção do eixo Ox e encontra-se imersa num campo magnético uniforme ® B, cujas componentes, em relação a Ox e Oz (em que z é perpendicular a xy) são, respectivamente, !$ B_x = 2,2 \,T !$ e !$ B_z = –0,50\,T !$. Assinale o módulo da força eletromotriz induzida na haste.
Provas
Questão presente nas seguintes provas
Uma espira retangular é colocada em um campo magnético com o plano da espira perpendicular à direção do campo, conforme mostra a figura. Se a corrente elétrica flui no sentido mostrado, pode-se afirmar em relação à resultante das forças, e ao torque total em relação ao centro da espira, que
Provas
Questão presente nas seguintes provas
Um elemento galvânico é constituído pelos eletrodos abaixo especificados, ligados por uma ponte salina e conectados a um multímetro de alta impedância.
Eletrodo a: Placa de chumbo metálico mergulhada em uma solução aquosa !$ 1 \,mol\, L^{–1} !$ de nitrato de chumbo.
Eletrodo b: Placa de níquel metálico mergulhada em uma solução aquosa !$ 1 \,mol\, L^{–1} !$ de sulfato de níquel.
Após estabelecido o equilíbrio químico nas condições padrão, determina-se a polaridade dos eletrodos. A seguir, são adicionadas pequenas porções de KI sólido ao Eletrodo a, até que ocorra a inversão de polaridade do elemento galvânico.
Dados eventualmente necessários:
Produto de solubilidade de !$ PbI_2: K_{ps} (PbI_2) = 8,5 × 10^{–9} !$
Potenciais de eletrodo em relação ao eletrodo padrão de hidrogênio nas condições-padrão:
!$ E^0_{Pb/Pb^2+} = – 0,13V !$ ; !$ E^0_{Ni/Ni^2+} = – 0,25V !$; !$ E^0_{I –/I2} = 0,53V !$
Assinale a opção que indica a concentração CORRETA de KI, em !$ mol\, L^{–1} !$, a partir da qual se observa a inversão de polaridade dos eletrodos nas condições-padrão.
Provas
Questão presente nas seguintes provas
No modelo proposto por Einstein, a luz se comporta como se sua energia estivesse concentrada em pacotes discretos, chamados de "quanta" de luz, e atualmente conhecidos por fótons. Estes possuem momento p e energia E relacionados pela equação E = pc, em que c é a velocidade da luz no vácuo. Cada fóton carrega uma energia E = hf, em que h é a constante de Planck e f é a freqüência da luz. Um evento raro, porém possível, é a fusão de dois fótons, produzindo um par elétron-pósitron, sendo a massa do pósitron igual à massa do elétron. A relação de Einstein associa a energia da partícula à massa do elétron ou pósitron, isto é, !$ E=m_ec^2 !$. Assinale a freqüência mínima
de cada fóton, para que dois fótons, com momentos opostos e de módulo iguais, produzam um par elétronpósitron após a colisão:
Provas
Questão presente nas seguintes provas
Cadernos
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