Foram encontradas 395 questões.
Based on your interpretation of the following texts, determine whether each statement is right or wrong.
Text 1
(from The Economist print edition, March 30th – April 5th 2013)
Excerpts from:
Climate science
A sensitive matter
The climate may be heating up less in response to greenhouse-gas emissions than was once thought. But that does not mean the problem is going away
OVER the past 15 years air temperatures at the Earth’s surface have been flat while greenhouse-gas emissions have continued to soar. The world added roughly 100 billion tonnes of carbon to the atmosphere between 2000 and 2010. That is about a quarter of all the CO₂ put there by humanity since 1750. And yet, as James Hansen, the head of NASA’s Goddard Institute for Space Studies, observes, “the five-year mean global temperature has been flat for a decade.”
Temperatures fluctuate over short periods, but this lack of new warming is a surprise. Ed Hawkins, of the University of Reading, in Britain, points out that surface temperatures since 2005 are already at the low end of the range of projections derived from 20 climate models (…). If they remain flat, they will fall outside the models’ range within a few years.
The mismatch between rising greenhouse-gas emissions and not-rising temperatures is among the biggest puzzles in climate science just now. It does not mean global warming is a delusion. Flat though they are, temperatures in the first decade of the 21st century remain almost 1°C above their level in the first decade of the 20th. But the puzzle does
need explaining. (…)
The insensitive planet
The term scientists use to describe the way the climate reacts to changes in carbon-dioxide levels is “climate sensitivity”. This is usually defined as how much hotter the Earth will get for each doubling of CO₂ concentrations. So-called equilibrium sensitivity, the commonest measure, refers to the temperature rise after allowing all feedback mechanisms to work (but without accounting for changes in vegetation and ice sheets).
Carbon dioxide itself absorbs infra-red at a consistent rate. For each doubling of CO₂ levels you get roughly 1°C of warming. A rise in concentrations from preindustrial levels of 280 parts per million (ppm) to 560ppm would thus warm the Earth by 1°C. If that were all there was to worry about, there would, as it were, be nothing to worry about. A 1°C rise could be shrugged off. But things are not that simple, for two reasons. One is that rising CO₂ levels directly influence phenomena such as the amount of water vapour (also a greenhouse gas) and clouds that amplify or diminish the temperature rise. This affects equilibrium sensitivity directly, meaning doubling carbon concentrations would produce more than a 1°C rise in temperature. The second is that other things, such as adding soot and other aerosols to the atmosphere, add to or subtract from the effect of CO₂. All serious climate scientists agree on these two lines of reasoning. But they disagree on the size of the change that is predicted.
(...)
According to the text:
Item 2 - Ed Hawkins and James Hansen are colleagues at Reading University;
Provas
Questão presente nas seguintes provas
Analisar a veracidade do item abaixo:
Item 4 - A função !$ f(x,y)=(ax+by,cx+dy) !$ é bijetora se e só !$ ad ≠ bc !$.
Provas
Questão presente nas seguintes provas
Sobre a economia brasileira nas últimas duas décadas, pode-se afirmar:
Item 3 - a carga tributária bruta em relação ao PIB manteve-se relativamente estável nos primeiros anos após a adoção do Plano Real, mas começou a crescer no final da década de 1990, tendência esta que se manteve nos primeiros cinco anos do século XXI.
Provas
Questão presente nas seguintes provas
Julgue o item abaixo:
Item 4 - Suponha que W e V sejam variáveis aleatórias que possuem distribuições qui-quadrado independentes, com graus de liberdade m e k, respectivamente. Então, !$ F=\large{^W/m \over ^V/k} !$ tem distribuição F com graus de liberdade m e k.
Provas
Questão presente nas seguintes provas
Based on your interpretation of the following texts, determine whether each statement is right or wrong.
Text 1
(from The Economist print edition, March 30th – April 5th 2013)
Excerpts from:
Climate science
A sensitive matter
The climate may be heating up less in response to greenhouse-gas emissions than was once thought. But that does not mean the problem is going away
OVER the past 15 years air temperatures at the Earth’s surface have been flat while greenhouse-gas emissions have continued to soar. The world added roughly 100 billion tonnes of carbon to the atmosphere between 2000 and 2010. That is about a quarter of all the CO₂ put there by humanity since 1750. And yet, as James Hansen, the head of NASA’s Goddard Institute for Space Studies, observes, “the five-year mean global temperature has been flat for a decade.”
Temperatures fluctuate over short periods, but this lack of new warming is a surprise. Ed Hawkins, of the University of Reading, in Britain, points out that surface temperatures since 2005 are already at the low end of the range of projections derived from 20 climate models (…). If they remain flat, they will fall outside the models’ range within a few years.
The mismatch between rising greenhouse-gas emissions and not-rising temperatures is among the biggest puzzles in climate science just now. It does not mean global warming is a delusion. Flat though they are, temperatures in the first decade of the 21st century remain almost 1°C above their level in the first decade of the 20th. But the puzzle does
need explaining. (…)
The insensitive planet
The term scientists use to describe the way the climate reacts to changes in carbon-dioxide levels is “climate sensitivity”. This is usually defined as how much hotter the Earth will get for each doubling of CO₂ concentrations. So-called equilibrium sensitivity, the commonest measure, refers to the temperature rise after allowing all feedback mechanisms to work (but without accounting for changes in vegetation and ice sheets).
Carbon dioxide itself absorbs infra-red at a consistent rate. For each doubling of CO₂ levels you get roughly 1°C of warming. A rise in concentrations from preindustrial levels of 280 parts per million (ppm) to 560ppm would thus warm the Earth by 1°C. If that were all there was to worry about, there would, as it were, be nothing to worry about. A 1°C rise could be shrugged off. But things are not that simple, for two reasons. One is that rising CO₂ levels directly influence phenomena such as the amount of water vapour (also a greenhouse gas) and clouds that amplify or diminish the temperature rise. This affects equilibrium sensitivity directly, meaning doubling carbon concentrations would produce more than a 1°C rise in temperature. The second is that other things, such as adding soot and other aerosols to the atmosphere, add to or subtract from the effect of CO₂. All serious climate scientists agree on these two lines of reasoning. But they disagree on the size of the change that is predicted.
(...)
According to the text:
Item 3 - The mismatch between rising greenhouse-gas emissions and temperatures not rising is mystifying climate scientists;
Provas
Questão presente nas seguintes provas
Based on your interpretation of the following texts, determine whether each statement is right or wrong.
Text 1
(from The Economist print edition, March 30th – April 5th 2013)
Excerpts from:
Climate science
A sensitive matter
The climate may be heating up less in response to greenhouse-gas emissions than was once thought. But that does not mean the problem is going away
OVER the past 15 years air temperatures at the Earth’s surface have been flat while greenhouse-gas emissions have continued to soar. The world added roughly 100 billion tonnes of carbon to the atmosphere between 2000 and 2010. That is about a quarter of all the CO₂ put there by humanity since 1750. And yet, as James Hansen, the head of NASA’s Goddard Institute for Space Studies, observes, “the five-year mean global temperature has been flat for a decade.”
Temperatures fluctuate over short periods, but this lack of new warming is a surprise. Ed Hawkins, of the University of Reading, in Britain, points out that surface temperatures since 2005 are already at the low end of the range of projections derived from 20 climate models (…). If they remain flat, they will fall outside the models’ range within a few years.
The mismatch between rising greenhouse-gas emissions and not-rising temperatures is among the biggest puzzles in climate science just now. It does not mean global warming is a delusion. Flat though they are, temperatures in the first decade of the 21st century remain almost 1°C above their level in the first decade of the 20th. But the puzzle does
need explaining. (…)
The insensitive planet
The term scientists use to describe the way the climate reacts to changes in carbon-dioxide levels is “climate sensitivity”. This is usually defined as how much hotter the Earth will get for each doubling of CO₂ concentrations. So-called equilibrium sensitivity, the commonest measure, refers to the temperature rise after allowing all feedback mechanisms to work (but without accounting for changes in vegetation and ice sheets).
Carbon dioxide itself absorbs infra-red at a consistent rate. For each doubling of CO₂ levels you get roughly 1°C of warming. A rise in concentrations from preindustrial levels of 280 parts per million (ppm) to 560ppm would thus warm the Earth by 1°C. If that were all there was to worry about, there would, as it were, be nothing to worry about. A 1°C rise could be shrugged off. But things are not that simple, for two reasons. One is that rising CO₂ levels directly influence phenomena such as the amount of water vapour (also a greenhouse gas) and clouds that amplify or diminish the temperature rise. This affects equilibrium sensitivity directly, meaning doubling carbon concentrations would produce more than a 1°C rise in temperature. The second is that other things, such as adding soot and other aerosols to the atmosphere, add to or subtract from the effect of CO₂. All serious climate scientists agree on these two lines of reasoning. But they disagree on the size of the change that is predicted.
(...)
According to the text:
Item 2 - Greenhouse-gas emissions have stabilised;
Provas
Questão presente nas seguintes provas
Considere uma função !$ f:R \rightarrow R\ !$ tal que exista a derivada. Suponha que !$ f'(x)>f(x) !$ sempre. Julgue o item abaixo:
Item 0 - !$ g(x)=e^{-x}f(x) !$ é estritamente crescente.
Provas
Questão presente nas seguintes provas
Sobre as interpretações da industrialização via processo de substituição de importações pode-se afirmar que:
Item 3 - há consenso de que a falta de competição seria responsável pelos altos custos internos e pela incapacidade de entrada dos produtos manufaturados brasileiros no mercado internacional.
Provas
Questão presente nas seguintes provas
Classifique a afirmativa como certo ou errado:
Item 3 - O Q de Tobin é medido pela razão valor de mercado do capital instalado sobre o custo de substituição do capital instalado;
Provas
Questão presente nas seguintes provas
Sobre os planos de combate à inflação das décadas de 1980 e 1990 pode-se afirmar:
Item 2 - a URV, no Plano Real, foi utilizada como reserva de valor.
Provas
Questão presente nas seguintes provas
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