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Prova de 2014: Universidade Estadual do Ceará (UECE) — questões com gabarito

356 questões da prova de 2014 de Universidade Estadual do Ceará (UECE), em Biologia, Inglês, Física. Cada uma tem página própria, com enunciado completo, alternativas e gabarito — e dá para responder na própria página.

  • 356 questões

Resultados: 356 questões

Página 10 de 18

  • Ciências da Natureza

    Biologia

    O Reino Vegetal é formado por diferentes tipos de plantas. Nesse Reino, a principal característica que diferencia samambaias e cajueiros é
    Escolha uma alternativa para a questão c04f3f26-b8
  • Ciências da Natureza

    Biologia

    Os recifes de corais são ecossistemas de grande biodiversidade, formados principalmente por carbonato de cálcio, proveniente de esqueletos de animais e algas coralinas que se depositam nos oceanos ao longo de milhares de anos. Sobre os recifes de corais, pode-se afirmar corretamente que
    Escolha uma alternativa para a questão c0521c90-b8
  • Ciências da Natureza

    Biologia

    Mesmo para os casais apaixonados, os beijos podem ser a porta de entrada de diversas doenças. Dentre as opções abaixo, são transmitidas somente pela saliva:
    Escolha uma alternativa para a questão c0550296-b8
  • Linguagens

    Inglês

    TEXT

        For a $14.95 monthly membership, the website Lumosity promises to “train” your brain with games designed to stave off mental decline. Users view a quick succession of bird images and numbers to test attention span, for instance, or match increasingly complex tile patterns to challenge memory.

        While Lumosity is perhaps the best known of the brain-game websites, with 50 million subscribers in 180 countries, the cognitive training business is booming. Happy Neuron of Mountain View, Calif., promises “brain fitness for life.” Cogmed, owned by the British education company Pearson, says its training program will give students “improved attention and capacity for learning.” The Israeli firm NeurMuch of the focus of theonix is developing a brain stimulation and cognitive training program that the company calls a “new hope for Alzheimer’s disease.”

        Much of the focus of the brain fitness business has been on helping children with attention-deficit problems, and on improving cognitive function and academic performance in healthy children and adults. An effective way to stave off memory loss or prevent Alzheimer’s — particularly

        The problem, Dr. Doraiswa if it were a simple website or video game — is the “holy grail” of neuroscience, said Dr. Murali Doraiswamy, director of the neurocognitive disorders program at Duke Institute for Brain Sciences. The problem, Dr. Doraiswamy added, is that the science of cognitive training has not kept up with the hype. “Almost all the marketing claims made by all the companies go beyond the data,” he said. “We need large national studies before you can conclude that it’s ready for prime time.”

        For centuries, scientists believed that most brain development occurred in the first few years of life — that by adulthood the brain was largely immutable. But over the past two decades, studies on animals and humans have found that the brain continues to form new neural connections throughout life. But questions remain whether an intervention that challenges the brain — a puzzle, studying a new language or improving skill on a video game — can really raise intelligence or stave off normal memory loss.

        A series of studies in recent years has suggested that certain types of game training can improve a person’s cognitive performance. In February 2013, however, an analysis of 23 of the best studies on brain training, led by the University of Oslo researcher Monica Melby-Lervag, concluded that while players do get better, the increase in skill hasn’t been shown to transfer to other tasks. In other words, playing Sudoku or an online matching game makes you better at the game, but it doesn’t make you better at math or help you remember names or where you left your car keys.

        But other studies have been more encouraging. Last September, the journal Nature published a study by researchers at the University of California, San Francisco, that showed a driving game did improve short-term memory and longterm focus in older adults. The findings are significant because the research found that improvements in performance weren’t limited to the game, but also appeared to be linked to a strengthening of older brains over all, helping them to perform better at other memory and attention tasks.

        In addition, brain monitoring during the study showed that in older participants, game training led to bursts in brain waves associated with attention; the patterns were similar to those seen in much younger brains.

        Earlier this year, the National Institutes of Health invited applications to more rigorously test brain fitness training to stave off cognitive decline. Researchers say they hope the effort will help establish a consistent standard for determining whether a brain-training intervention works.

        But while the science remains unclear, entrepreneurs have seized on what is likely to be a sizable marketing opportunity. In May, hundreds of researchers and businesses will gather in San Francisco for the NeuroGaming Conference and Expo to explore the latest research and the newest technology.

        While there is no real risk to participating in the many unproven brain-training games available online and through smartphones, experts say, consumers should know that the scientific jury is still out on whether they are really boosting brain health or just paying hundreds of dollars to get better at a game.

        “I’m not convinced there is a huge difference between buying a $300 subscription to a gaming company versus you yourself doing challenging things on your own, like attending a lecture or learning an instrument,” Dr. Doraiswamy said. “Each person has to personalize for themselves what they find fun and challenging and what they can stick with.”

    From: www.nytimes.com, March 10, 2014

    The idea that the brain ceases to develop at a very young age
    Escolha uma alternativa para a questão c057ef07-b8
  • Linguagens

    Inglês

    TEXT

        For a $14.95 monthly membership, the website Lumosity promises to “train” your brain with games designed to stave off mental decline. Users view a quick succession of bird images and numbers to test attention span, for instance, or match increasingly complex tile patterns to challenge memory.

        While Lumosity is perhaps the best known of the brain-game websites, with 50 million subscribers in 180 countries, the cognitive training business is booming. Happy Neuron of Mountain View, Calif., promises “brain fitness for life.” Cogmed, owned by the British education company Pearson, says its training program will give students “improved attention and capacity for learning.” The Israeli firm NeurMuch of the focus of theonix is developing a brain stimulation and cognitive training program that the company calls a “new hope for Alzheimer’s disease.”

        Much of the focus of the brain fitness business has been on helping children with attention-deficit problems, and on improving cognitive function and academic performance in healthy children and adults. An effective way to stave off memory loss or prevent Alzheimer’s — particularly

        The problem, Dr. Doraiswa if it were a simple website or video game — is the “holy grail” of neuroscience, said Dr. Murali Doraiswamy, director of the neurocognitive disorders program at Duke Institute for Brain Sciences. The problem, Dr. Doraiswamy added, is that the science of cognitive training has not kept up with the hype. “Almost all the marketing claims made by all the companies go beyond the data,” he said. “We need large national studies before you can conclude that it’s ready for prime time.”

        For centuries, scientists believed that most brain development occurred in the first few years of life — that by adulthood the brain was largely immutable. But over the past two decades, studies on animals and humans have found that the brain continues to form new neural connections throughout life. But questions remain whether an intervention that challenges the brain — a puzzle, studying a new language or improving skill on a video game — can really raise intelligence or stave off normal memory loss.

        A series of studies in recent years has suggested that certain types of game training can improve a person’s cognitive performance. In February 2013, however, an analysis of 23 of the best studies on brain training, led by the University of Oslo researcher Monica Melby-Lervag, concluded that while players do get better, the increase in skill hasn’t been shown to transfer to other tasks. In other words, playing Sudoku or an online matching game makes you better at the game, but it doesn’t make you better at math or help you remember names or where you left your car keys.

        But other studies have been more encouraging. Last September, the journal Nature published a study by researchers at the University of California, San Francisco, that showed a driving game did improve short-term memory and longterm focus in older adults. The findings are significant because the research found that improvements in performance weren’t limited to the game, but also appeared to be linked to a strengthening of older brains over all, helping them to perform better at other memory and attention tasks.

        In addition, brain monitoring during the study showed that in older participants, game training led to bursts in brain waves associated with attention; the patterns were similar to those seen in much younger brains.

        Earlier this year, the National Institutes of Health invited applications to more rigorously test brain fitness training to stave off cognitive decline. Researchers say they hope the effort will help establish a consistent standard for determining whether a brain-training intervention works.

        But while the science remains unclear, entrepreneurs have seized on what is likely to be a sizable marketing opportunity. In May, hundreds of researchers and businesses will gather in San Francisco for the NeuroGaming Conference and Expo to explore the latest research and the newest technology.

        While there is no real risk to participating in the many unproven brain-training games available online and through smartphones, experts say, consumers should know that the scientific jury is still out on whether they are really boosting brain health or just paying hundreds of dollars to get better at a game.

        “I’m not convinced there is a huge difference between buying a $300 subscription to a gaming company versus you yourself doing challenging things on your own, like attending a lecture or learning an instrument,” Dr. Doraiswamy said. “Each person has to personalize for themselves what they find fun and challenging and what they can stick with.”

    From: www.nytimes.com, March 10, 2014

    According to Dr. Doraiswamy, from the Duke Institute for Brain Sciences, the problem about many of the cognitive training programs being offered nowadays is that
    Escolha uma alternativa para a questão c05ae75a-b8
  • Linguagens

    Inglês

    TEXT

        For a $14.95 monthly membership, the website Lumosity promises to “train” your brain with games designed to stave off mental decline. Users view a quick succession of bird images and numbers to test attention span, for instance, or match increasingly complex tile patterns to challenge memory.

        While Lumosity is perhaps the best known of the brain-game websites, with 50 million subscribers in 180 countries, the cognitive training business is booming. Happy Neuron of Mountain View, Calif., promises “brain fitness for life.” Cogmed, owned by the British education company Pearson, says its training program will give students “improved attention and capacity for learning.” The Israeli firm NeurMuch of the focus of theonix is developing a brain stimulation and cognitive training program that the company calls a “new hope for Alzheimer’s disease.”

        Much of the focus of the brain fitness business has been on helping children with attention-deficit problems, and on improving cognitive function and academic performance in healthy children and adults. An effective way to stave off memory loss or prevent Alzheimer’s — particularly

        The problem, Dr. Doraiswa if it were a simple website or video game — is the “holy grail” of neuroscience, said Dr. Murali Doraiswamy, director of the neurocognitive disorders program at Duke Institute for Brain Sciences. The problem, Dr. Doraiswamy added, is that the science of cognitive training has not kept up with the hype. “Almost all the marketing claims made by all the companies go beyond the data,” he said. “We need large national studies before you can conclude that it’s ready for prime time.”

        For centuries, scientists believed that most brain development occurred in the first few years of life — that by adulthood the brain was largely immutable. But over the past two decades, studies on animals and humans have found that the brain continues to form new neural connections throughout life. But questions remain whether an intervention that challenges the brain — a puzzle, studying a new language or improving skill on a video game — can really raise intelligence or stave off normal memory loss.

        A series of studies in recent years has suggested that certain types of game training can improve a person’s cognitive performance. In February 2013, however, an analysis of 23 of the best studies on brain training, led by the University of Oslo researcher Monica Melby-Lervag, concluded that while players do get better, the increase in skill hasn’t been shown to transfer to other tasks. In other words, playing Sudoku or an online matching game makes you better at the game, but it doesn’t make you better at math or help you remember names or where you left your car keys.

        But other studies have been more encouraging. Last September, the journal Nature published a study by researchers at the University of California, San Francisco, that showed a driving game did improve short-term memory and longterm focus in older adults. The findings are significant because the research found that improvements in performance weren’t limited to the game, but also appeared to be linked to a strengthening of older brains over all, helping them to perform better at other memory and attention tasks.

        In addition, brain monitoring during the study showed that in older participants, game training led to bursts in brain waves associated with attention; the patterns were similar to those seen in much younger brains.

        Earlier this year, the National Institutes of Health invited applications to more rigorously test brain fitness training to stave off cognitive decline. Researchers say they hope the effort will help establish a consistent standard for determining whether a brain-training intervention works.

        But while the science remains unclear, entrepreneurs have seized on what is likely to be a sizable marketing opportunity. In May, hundreds of researchers and businesses will gather in San Francisco for the NeuroGaming Conference and Expo to explore the latest research and the newest technology.

        While there is no real risk to participating in the many unproven brain-training games available online and through smartphones, experts say, consumers should know that the scientific jury is still out on whether they are really boosting brain health or just paying hundreds of dollars to get better at a game.

        “I’m not convinced there is a huge difference between buying a $300 subscription to a gaming company versus you yourself doing challenging things on your own, like attending a lecture or learning an instrument,” Dr. Doraiswamy said. “Each person has to personalize for themselves what they find fun and challenging and what they can stick with.”

    From: www.nytimes.com, March 10, 2014

    Among the promises made by websites for their cognitive training programs, one may list
    Escolha uma alternativa para a questão c05dd253-b8
  • Linguagens

    Inglês

    TEXT

        For a $14.95 monthly membership, the website Lumosity promises to “train” your brain with games designed to stave off mental decline. Users view a quick succession of bird images and numbers to test attention span, for instance, or match increasingly complex tile patterns to challenge memory.

        While Lumosity is perhaps the best known of the brain-game websites, with 50 million subscribers in 180 countries, the cognitive training business is booming. Happy Neuron of Mountain View, Calif., promises “brain fitness for life.” Cogmed, owned by the British education company Pearson, says its training program will give students “improved attention and capacity for learning.” The Israeli firm NeurMuch of the focus of theonix is developing a brain stimulation and cognitive training program that the company calls a “new hope for Alzheimer’s disease.”

        Much of the focus of the brain fitness business has been on helping children with attention-deficit problems, and on improving cognitive function and academic performance in healthy children and adults. An effective way to stave off memory loss or prevent Alzheimer’s — particularly

        The problem, Dr. Doraiswa if it were a simple website or video game — is the “holy grail” of neuroscience, said Dr. Murali Doraiswamy, director of the neurocognitive disorders program at Duke Institute for Brain Sciences. The problem, Dr. Doraiswamy added, is that the science of cognitive training has not kept up with the hype. “Almost all the marketing claims made by all the companies go beyond the data,” he said. “We need large national studies before you can conclude that it’s ready for prime time.”

        For centuries, scientists believed that most brain development occurred in the first few years of life — that by adulthood the brain was largely immutable. But over the past two decades, studies on animals and humans have found that the brain continues to form new neural connections throughout life. But questions remain whether an intervention that challenges the brain — a puzzle, studying a new language or improving skill on a video game — can really raise intelligence or stave off normal memory loss.

        A series of studies in recent years has suggested that certain types of game training can improve a person’s cognitive performance. In February 2013, however, an analysis of 23 of the best studies on brain training, led by the University of Oslo researcher Monica Melby-Lervag, concluded that while players do get better, the increase in skill hasn’t been shown to transfer to other tasks. In other words, playing Sudoku or an online matching game makes you better at the game, but it doesn’t make you better at math or help you remember names or where you left your car keys.

        But other studies have been more encouraging. Last September, the journal Nature published a study by researchers at the University of California, San Francisco, that showed a driving game did improve short-term memory and longterm focus in older adults. The findings are significant because the research found that improvements in performance weren’t limited to the game, but also appeared to be linked to a strengthening of older brains over all, helping them to perform better at other memory and attention tasks.

        In addition, brain monitoring during the study showed that in older participants, game training led to bursts in brain waves associated with attention; the patterns were similar to those seen in much younger brains.

        Earlier this year, the National Institutes of Health invited applications to more rigorously test brain fitness training to stave off cognitive decline. Researchers say they hope the effort will help establish a consistent standard for determining whether a brain-training intervention works.

        But while the science remains unclear, entrepreneurs have seized on what is likely to be a sizable marketing opportunity. In May, hundreds of researchers and businesses will gather in San Francisco for the NeuroGaming Conference and Expo to explore the latest research and the newest technology.

        While there is no real risk to participating in the many unproven brain-training games available online and through smartphones, experts say, consumers should know that the scientific jury is still out on whether they are really boosting brain health or just paying hundreds of dollars to get better at a game.

        “I’m not convinced there is a huge difference between buying a $300 subscription to a gaming company versus you yourself doing challenging things on your own, like attending a lecture or learning an instrument,” Dr. Doraiswamy said. “Each person has to personalize for themselves what they find fun and challenging and what they can stick with.”

    From: www.nytimes.com, March 10, 2014

    Recent research undertaken with older adults at the University of California presented significant results in relation to cognitive training using a certain driving game. They are significant due to the evidence that
    Escolha uma alternativa para a questão c060efe2-b8
  • Linguagens

    Inglês

    TEXT

        For a $14.95 monthly membership, the website Lumosity promises to “train” your brain with games designed to stave off mental decline. Users view a quick succession of bird images and numbers to test attention span, for instance, or match increasingly complex tile patterns to challenge memory.

        While Lumosity is perhaps the best known of the brain-game websites, with 50 million subscribers in 180 countries, the cognitive training business is booming. Happy Neuron of Mountain View, Calif., promises “brain fitness for life.” Cogmed, owned by the British education company Pearson, says its training program will give students “improved attention and capacity for learning.” The Israeli firm NeurMuch of the focus of theonix is developing a brain stimulation and cognitive training program that the company calls a “new hope for Alzheimer’s disease.”

        Much of the focus of the brain fitness business has been on helping children with attention-deficit problems, and on improving cognitive function and academic performance in healthy children and adults. An effective way to stave off memory loss or prevent Alzheimer’s — particularly

        The problem, Dr. Doraiswa if it were a simple website or video game — is the “holy grail” of neuroscience, said Dr. Murali Doraiswamy, director of the neurocognitive disorders program at Duke Institute for Brain Sciences. The problem, Dr. Doraiswamy added, is that the science of cognitive training has not kept up with the hype. “Almost all the marketing claims made by all the companies go beyond the data,” he said. “We need large national studies before you can conclude that it’s ready for prime time.”

        For centuries, scientists believed that most brain development occurred in the first few years of life — that by adulthood the brain was largely immutable. But over the past two decades, studies on animals and humans have found that the brain continues to form new neural connections throughout life. But questions remain whether an intervention that challenges the brain — a puzzle, studying a new language or improving skill on a video game — can really raise intelligence or stave off normal memory loss.

        A series of studies in recent years has suggested that certain types of game training can improve a person’s cognitive performance. In February 2013, however, an analysis of 23 of the best studies on brain training, led by the University of Oslo researcher Monica Melby-Lervag, concluded that while players do get better, the increase in skill hasn’t been shown to transfer to other tasks. In other words, playing Sudoku or an online matching game makes you better at the game, but it doesn’t make you better at math or help you remember names or where you left your car keys.

        But other studies have been more encouraging. Last September, the journal Nature published a study by researchers at the University of California, San Francisco, that showed a driving game did improve short-term memory and longterm focus in older adults. The findings are significant because the research found that improvements in performance weren’t limited to the game, but also appeared to be linked to a strengthening of older brains over all, helping them to perform better at other memory and attention tasks.

        In addition, brain monitoring during the study showed that in older participants, game training led to bursts in brain waves associated with attention; the patterns were similar to those seen in much younger brains.

        Earlier this year, the National Institutes of Health invited applications to more rigorously test brain fitness training to stave off cognitive decline. Researchers say they hope the effort will help establish a consistent standard for determining whether a brain-training intervention works.

        But while the science remains unclear, entrepreneurs have seized on what is likely to be a sizable marketing opportunity. In May, hundreds of researchers and businesses will gather in San Francisco for the NeuroGaming Conference and Expo to explore the latest research and the newest technology.

        While there is no real risk to participating in the many unproven brain-training games available online and through smartphones, experts say, consumers should know that the scientific jury is still out on whether they are really boosting brain health or just paying hundreds of dollars to get better at a game.

        “I’m not convinced there is a huge difference between buying a $300 subscription to a gaming company versus you yourself doing challenging things on your own, like attending a lecture or learning an instrument,” Dr. Doraiswamy said. “Each person has to personalize for themselves what they find fun and challenging and what they can stick with.”

    From: www.nytimes.com, March 10, 2014

    While scientific research and brain gaming companies are not working with the same assumptions, Dr. Doraiswamy recommends that people
    Escolha uma alternativa para a questão c06475dc-b8
  • Linguagens

    Inglês

    TEXT

        For a $14.95 monthly membership, the website Lumosity promises to “train” your brain with games designed to stave off mental decline. Users view a quick succession of bird images and numbers to test attention span, for instance, or match increasingly complex tile patterns to challenge memory.

        While Lumosity is perhaps the best known of the brain-game websites, with 50 million subscribers in 180 countries, the cognitive training business is booming. Happy Neuron of Mountain View, Calif., promises “brain fitness for life.” Cogmed, owned by the British education company Pearson, says its training program will give students “improved attention and capacity for learning.” The Israeli firm NeurMuch of the focus of theonix is developing a brain stimulation and cognitive training program that the company calls a “new hope for Alzheimer’s disease.”

        Much of the focus of the brain fitness business has been on helping children with attention-deficit problems, and on improving cognitive function and academic performance in healthy children and adults. An effective way to stave off memory loss or prevent Alzheimer’s — particularly

        The problem, Dr. Doraiswa if it were a simple website or video game — is the “holy grail” of neuroscience, said Dr. Murali Doraiswamy, director of the neurocognitive disorders program at Duke Institute for Brain Sciences. The problem, Dr. Doraiswamy added, is that the science of cognitive training has not kept up with the hype. “Almost all the marketing claims made by all the companies go beyond the data,” he said. “We need large national studies before you can conclude that it’s ready for prime time.”

        For centuries, scientists believed that most brain development occurred in the first few years of life — that by adulthood the brain was largely immutable. But over the past two decades, studies on animals and humans have found that the brain continues to form new neural connections throughout life. But questions remain whether an intervention that challenges the brain — a puzzle, studying a new language or improving skill on a video game — can really raise intelligence or stave off normal memory loss.

        A series of studies in recent years has suggested that certain types of game training can improve a person’s cognitive performance. In February 2013, however, an analysis of 23 of the best studies on brain training, led by the University of Oslo researcher Monica Melby-Lervag, concluded that while players do get better, the increase in skill hasn’t been shown to transfer to other tasks. In other words, playing Sudoku or an online matching game makes you better at the game, but it doesn’t make you better at math or help you remember names or where you left your car keys.

        But other studies have been more encouraging. Last September, the journal Nature published a study by researchers at the University of California, San Francisco, that showed a driving game did improve short-term memory and longterm focus in older adults. The findings are significant because the research found that improvements in performance weren’t limited to the game, but also appeared to be linked to a strengthening of older brains over all, helping them to perform better at other memory and attention tasks.

        In addition, brain monitoring during the study showed that in older participants, game training led to bursts in brain waves associated with attention; the patterns were similar to those seen in much younger brains.

        Earlier this year, the National Institutes of Health invited applications to more rigorously test brain fitness training to stave off cognitive decline. Researchers say they hope the effort will help establish a consistent standard for determining whether a brain-training intervention works.

        But while the science remains unclear, entrepreneurs have seized on what is likely to be a sizable marketing opportunity. In May, hundreds of researchers and businesses will gather in San Francisco for the NeuroGaming Conference and Expo to explore the latest research and the newest technology.

        While there is no real risk to participating in the many unproven brain-training games available online and through smartphones, experts say, consumers should know that the scientific jury is still out on whether they are really boosting brain health or just paying hundreds of dollars to get better at a game.

        “I’m not convinced there is a huge difference between buying a $300 subscription to a gaming company versus you yourself doing challenging things on your own, like attending a lecture or learning an instrument,” Dr. Doraiswamy said. “Each person has to personalize for themselves what they find fun and challenging and what they can stick with.”

    From: www.nytimes.com, March 10, 2014

    According to a study conducted by Monica Melby-Lervag at the University of Oslo, applying oneself to an activity such as playing Sudoku
    Escolha uma alternativa para a questão c06743b6-b8
  • Ciências da Natureza

    Física

    Uma bola é lançada do solo verticalmente para cima. Durante a subida e a descida do objeto, considere desprezíveis todos os atritos, assuma que o diâmetro da bola é muito menor que o comprimento da sua trajetória e que a única força atuando no objeto após o lançamento é a força da gravidade. Sobre o vetor aceleração da bola, é correto afirmar que tem direção vertical e sentido
    Escolha uma alternativa para a questão c611219f-b8
  • Ciências da Natureza

    Física

    Considere os sistemas massa-mola ilustrados na figura a seguir.

    Imagem da questão de Física, UECE 2014, Dinâmica

    As massas, nos dois sistemas, são iguais, as molas são idênticas, de constante elástica k e, quando livres, têm comprimento L. No sistema I, as molas estão igualmente comprimidas, e no II, estão igualmente distendidas, sendo possível movimento apenas na direção da linha que une os pontos de fixação das molas. Considere que as massas sejam deslocadas a uma distância x de suas posições de equilíbrio. Considere também que x é muito menor que a compressão inicial das molas em I e muito menor que a distensão inicial em II. Os módulos das forças resultantes nas massas no sistema I e II são, respectivamente,
    Escolha uma alternativa para a questão c61434f9-b8
  • Ciências da Natureza

    Física

    Comprimidos efervescentes em um copo d’água liberam gás carbônico na forma de bolhas que sobem para a superfície do líquido. A força responsável pela subida das bolhas é denominada
    Escolha uma alternativa para a questão c6171720-b8
  • Ciências da Natureza

    Física

    Considere o campo elétrico gerado por duas cargas elétricas puntiformes, de valores iguais e sinais contrários, separadas por uma distância d. Sobre esse vetor campo elétrico nos pontos equidistantes das cargas, é correto afirmar que
    Escolha uma alternativa para a questão c619e942-b8
  • Ciências da Natureza

    Física

    A potência dissipada por efeito joule em um resistor de R Ohms ligado a uma tensão de x Volts pode ser calculada como x²/R. Assim, a potência pode ser medida em
    Escolha uma alternativa para a questão c62015f4-b8
  • Ciências da Natureza

    Física

    Uma haste metálica reta de comprimento L0 e coeficiente de dilatação linear a é acomodada entre duas paredes rígidas. Após ter sua temperatura aumentada de ΔT, a haste se dilata e adquire a forma de um arco de círculo com um ângulo correspondente de θ radianos. Qual o raio desse arco de círculo?
    Escolha uma alternativa para a questão c62311d5-b8
  • Ciências da Natureza

    Física

    A ponta da hélice de um cata-vento descreve um movimento circular uniforme. Os vetores velocidade de um ponto localizado nessa extremidade nos tempos t e t + Δt são representados na figura a seguir.

    Imagem da questão de Física, UECE 2014, Cinemática

    Nesta figura, os vetores velocidade têm suas origens posicionadas sobre a ponta da hélice nos tempos t e t + Δt. Assim, é correto afirmar que o ponto gira no sentido
    Escolha uma alternativa para a questão c6263c64-b8
  • Ciências da Natureza

    Física

    Um carro trafega com velocidade constante, em módulo, em uma estrada onde um trecho pode ser aproximado por uma circunferência no plano vertical, conforme a figura a seguir.

    Imagem da questão de Física, UECE 2014, Cinemática

    Ao longo do trecho em que essa aproximação é válida, a soma de todas as forças atuando no carro, incluindo o vetor força normal da estrada sobre o carro e o vetor força peso do carro, é um vetor que aponta na direção
    Escolha uma alternativa para a questão c6290031-b8
  • Ciências da Natureza

    Física

    Um bloco de madeira é arrastado em linha reta sobre um piso horizontal. Considere que o bloco tem peso 10 N, o coeficiente de atrito estático entre o bloco e o piso é 0,7 e o cinético é 0,6. Inicialmente a força horizontal que move o bloco é de 8 N. Em um dado instante, esta força é reduzida instantaneamente para metade de seu valor. Transcorrido um tempo muito grande após essa redução, pode-se afirmar corretamente que a aceleração do bloco é
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  • Ciências da Natureza

    Física

    Uma onda sonora vinda de uma sirene chega a um determinado ponto próximo a um ouvinte. É correto afirmar que, em decorrência dessa onda sonora, nesse ponto há
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  • Ciências da Natureza

    Física

    Considere uma onda sonora gerada por uma fonte puntiforme e que se propaga em três dimensões em um meio isotrópico, não dispersivo e não dissipativo. Sobre a frente de onda próximo à fonte geradora, é correto afirmar que
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