Questõesde UECE 2018

1
1
Foram encontradas 300 questões
2704f953-03
UECE 2018 - Física - Oscilação e Ondas, Movimento Harmônico

Um oscilador harmônico simples, do tipo massa-mola, tem a posição de sua massa descrita por x = 2 ⋅ cos (3,14 ⋅ t ). Nesse sistema, a amplitude e a frequência são, respectivamente,

A
1/2 e 2.
B
2 e 3,14.
C
2 e 1/2.
D
3,14 e 2.
270126a0-03
UECE 2018 - Física - Fundamentos da Cinemática, Cinemática

Para fazer o transporte de peixes de um açude, um caminhão transporta um depósito cúbico de aresta A com água até sua metade em uma estrada plana horizontal ao longo de um comprimento de 10 km. A velocidade do caminhão é constante. O desnível θ da superfície da água no depósito em relação à superfície da estrada é tal que

A
cosθ = 1.
B
cosθ= 1/2.
C
cosθ= √3/2.
D
cosθ = √3.
26fce67d-03
UECE 2018 - Física - Oscilação e Ondas, Movimento Harmônico

Um fio de comprimento L, preso no teto, tem na sua outra extremidade uma massa m que constitui um pêndulo simples que oscila com período T . As partículas ao longo do fio têm

A
velocidades angulares diferentes.
B
mesma velocidade linear.
C
mesma velocidade angular.
D
não têm velocidade angular.
271229d0-03
UECE 2018 - Física - Ótica, Espelhos Planos

Considerando que, em um espelho plano incide um raio de luz, é correto afirmar que

A
o ângulo de incidência é sempre suplementar ao de reflexão.
B
o ângulo de reflexão é sempre perpendicular ao espelho.
C
o ângulo de incidência é igual ao de reflexão e a direção normal é perpendicular ao plano do espelho.
D
o ângulo entre a superfície do espelho e o raio incidente é sempre igual ao ângulo entre o raio refletido e a direção normal.
26e1a619-03
UECE 2018 - Física - Calorimetria, Física Térmica - Termologia, Gás Ideal

Um gás ideal tem seu estado termodinâmico completamente determinado pelas variáveis

A
pressão, volume e carga elétrica.
B
pressão, volume e temperatura.
C
pressão, carga elétrica e temperatura.
D
densidade, volume e gravidade.
26e57aa8-03
UECE 2018 - Física - Calorimetria, Física Térmica - Termologia, Gás Ideal

Um gás ideal, em um recipiente, é mantido em temperatura constante e em equilíbrio térmico com a vizinhança. Nesse gás, o produto da pressão pelo volume é

A
constante, independente de troca de massa com a vizinhança.
B
constante, desde que a razão entre temperatura e número de moles seja constante.
C
indefinido, pois o número de moles do gás só depende da temperatura.
D
constante, desde que não haja entrada ou saída de gás.
26e9248a-03
UECE 2018 - Física - Oscilação e Ondas, Movimento Harmônico

Em um sistema oscilante, a corrente elétrica é descrita por x = a ⋅ cos (b ⋅ t). As unidades de medida das constantes a e b são, respectivamente,

A
Hz e Ampére.
B
Ampére e Hz.
C
Ampére e segundo.
D
segundo e Ampére.
26ed1365-03
UECE 2018 - Física - Vetores, Conteúdos Básicos

Considere um trecho de estrada em descida seguido por uma subida. De modo simplificado, considere que esse trecho tem um formato de arco de círculo. Tratando um carro que passa por esse trecho como uma massa puntiforme, é correto afirmar que o vetor força normal da estrada sobre o carro

A
tem direção e sentido que sempre apontam para o centro do arco de círculo.
B
é sempre tangente à trajetória.
C
é sempre vertical.
D
é sempre horizontal.
26f32667-03
UECE 2018 - Física - Estática e Hidrostática, Hidrostática

A pressão hidrostática na base de uma coluna de líquido é

A

proporcional à razão

B
inversamente proporcional à altura.
C

proporcional à razão

D
inversamente proporcional à aceleração da gravidade.
26f90562-03
UECE 2018 - Física - Transformações Gasosas, Física Térmica - Termologia

Um sistema de massa constante, constituído por um gás ideal, está no estado inicial de volume V0 , pressão P0 e temperatura T0 . Quando o sistema evolui para um novo estado de volume V0/2 e pressão P0/2 , sua temperatura é

A
T0/2.
B
2T0.
C
T0.
D
T0/4.
26dc24d8-03
UECE 2018 - Física - Dinâmica, Trabalho e Energia, Grandezas e Unidades, Conteúdos Básicos

Considere a energia potencial gravitacional de uma massa puntiforme próxima à superfície da Terra. Suponha que a unidade de medida de comprimento no Sistema Internacional de Unidades fosse mudada para o centímetro. O valor numérico da energia potencial gravitacional, no sistema que usa centímetros, seria igual à do sistema original multiplicada por um fator de

A
10.
B
100.
C
1.000.
D
10.000.
26d6adb4-03
UECE 2018 - Física - MCUV - Movimento Circular Uniformemente Variado, MCU - Movimento Circular Uniforme, Cinemática

Em um relógio mecânico, os ponteiros de minuto e segundo têm velocidade angular, respectivamente,

A
60 rpm e 1 rpm.
B
60 radianos/s e 1 rpm.
C
1/60 rpm e 1 rpm.
D
1 radiano/s e 60 rpm.
26d31bff-03
UECE 2018 - Física - Estática e Hidrostática, Hidrostática

Recentemente os noticiários reportaram um caso de resgate de pessoas em uma caverna alagada. Um mergulhador submerso, durante o trajeto até o ponto de resgate, sofre uma pressão hidrostática devido à coluna d’água sobre ele. Tratando-o como puntiforme, essa pressão é dada pelo produto da

A
densidade da água, aceleração da gravidade e distância à superfície da água.
B
densidade da água, volume do mergulhador e aceleração da gravidade.
C
densidade do mergulhador, volume do mergulhador e aceleração da gravidade.
D
densidade da água, volume e temperatura do mergulhador.
26ce7d39-03
UECE 2018 - Física - Dinâmica, Leis de Newton

A mecânica newtoniana não é válida para descrever fenômenos que envolvam

A
massas que possam ser tratadas como puntiformes e em velocidades muito menores do que a da luz.
B
escala subatômica ou equilíbrio de corpos rígidos.
C
velocidades próximas à da luz.
D
oscilações harmônicas em sistemas do tipo massa-mola.
26c811a0-03
UECE 2018 - Física - Física Moderna, Física Atômica e Nuclear

Atualmente é bem difundido um exame de tomografia conhecido por PET-CT (acrônimo para Positron Emission Tomography with Computed Tomography). Nesse exame o paciente tem injetado em sua corrente sanguínea uma substância que emite radiação, especificamente na forma de pósitrons, que são detectados por componentes do tomógrafo. Os pósitrons têm a mesma massa do

A
próton e carga positiva.
B
próton e carga negativa.
C
nêutron e carga positiva.
D
elétron e carga positiva.
26bde390-03
UECE 2018 - Física - Dinâmica, Leis de Newton

No contexto da mecânica newtoniana, diz-se que uma massa puntiforme está em equilíbrio quando a soma

A
dos módulos das forças atuando nela é nula.
B
vetorial de todas as forças atuando nela é nula.
C
dos torques atuando nela é nula, calculados em relação a um eixo que passa pelo seu centro.
D
dos momentos lineares dela varia com o tempo.
1aa162c3-fa
UECE 2018 - Inglês - Vocabulário | Vocabulary, Interpretação de texto | Reading comprehension

Scott Cairney, one of the researchers responsible for the study, explains that the results are relevant to understand

                                         T E X T


                          Can you learn in your sleep?


      Sleep is known to be crucial for learning and memory formation. What's more, scientists have even managed to pick out specific memories and consolidate them during sleep. However, the exact mechanisms behind this were unknown — until now.

      Those among us who grew up with the popular cartoon "Dexter's Laboratory" might remember the famous episode wherein Dexter's trying to learn French overnight. He creates a device that helps him to learn in his sleep by playing French phrases to him. Of course, since the show is a comedy, Dexter's record gets stuck on the phrase "Omelette du fromage" and the next day he's incapable of saying anything else. This is, of course, a problem that puts him through a series of hilarious situations.

      The idea that we can learn in our sleep has captivated the minds of artists and scientists alike; the possibility that one day we could all drastically improve our productivity by learning in our sleep is very appealing. But could such a scenario ever become a reality?

      New research seems to suggest so, and scientists in general are moving closer to understanding precisely what goes on in the brain when we sleep and how the restful state affects learning and memory formation.

      For instance, previous studies have shown that non-rapid eye movement (non-REM) sleep — or dreamless sleep — is crucial for consolidating memories. It has also been shown that sleep spindles, or sudden spikes in oscillatory brain activity that can be seen on an electroencephalogram (EEG) during the second stage of non-REM sleep, are key for this memory consolidation. Scientists were also able to specifically target certain memories and reactivate, or strengthen, them by using auditory cues.

      However, the mechanism behind such achievements remained mysterious until now. Researchers were also unaware if such mechanisms would help with memorizing new information.

      Therefore, a team of researchers set out to investigate. Scott Cairney, from the University of York in the United Kingdom, co-led the research with Bernhard Staresina, who works at the University of Birmingham, also in the U.K. Their findings were published in the journal Current Biology.

      Cairney explains the motivation for the research, saying, "We are quite certain that memories are reactivated in the brain during sleep, but we don't know the neural processes that underpin this phenomenon." "Sleep spindles," he continues, "have been linked to the benefits of sleep for memory in previous research, so we wanted to investigate whether these brain waves mediate reactivation. If they support memory reactivation, we further reasoned that it could be possible to decipher memory signals at the time that these spindles took place."

      To test their hypotheses, Cairney and his colleagues asked 46 participants "to learn associations between words and pictures of objects or scenes before a nap." Afterward, some of the participants took a 90-minute nap, whereas others stayed awake. To those who napped, "Half of the words were [...] replayed during the nap to trigger the reactivation of the newly learned picture memories," explains Cairney.

      "When the participants woke after a good period of sleep," he says, "we presented them again with the words and asked them to recall the object and scene pictures. We found that their memory was better for the pictures that were connected to the words that were presented in sleep, compared to those words that weren't," Cairney reports.

      Using an EEG machine, the researchers were also able to see that playing the associated words to reactivate memories triggered sleep spindles in the participants' brains. More specifically, the EEG sleep spindle patterns "told" the researchers whether the participants were processing memories related to objects or memories related to scenes.

      "Our data suggest that spindles facilitate processing of relevant memory features during sleep and that this process boosts memory consolidation," says Staresina. "While it has been shown previously," he continues, "that targeted memory reactivation can boost memory consolidation during sleep, we now show that sleep spindles might represent the key underlying mechanism."

      Cairney adds, "When you are awake you learn new things, but when you are asleep you refine them, making it easier to retrieve them and apply them correctly when you need them the most. This is important for how we learn but also for how we might help retain healthy brain functions."

      Staresina suggests that this newly gained knowledge could lead to effective strategies for boosting memory while sleeping.

      So, though learning things from scratch à la "Dexter's Lab" may take a while to become a reality, we can safely say that our brains continue to learn while we sleep, and that researchers just got a lot closer to understanding why this happens.

                                From: https://www.medicalnewstoday.com/articles/Mar/2018

A
how much brain work is carried out while a person sleeps.
B
how our brain functions while we are dreaming.
C
the way we learn and the way we keep healthy brain functions.
D
the relation between brain activity in sleep and our mood after waking.
1a9da95d-fa
UECE 2018 - Inglês - Vocabulário | Vocabulary, Interpretação de texto | Reading comprehension

Another finding of the research is related to the electroencephalogram (EEG) that was done while the participants were sleeping and exposed to the replay of the words, which revealed

                                         T E X T


                          Can you learn in your sleep?


      Sleep is known to be crucial for learning and memory formation. What's more, scientists have even managed to pick out specific memories and consolidate them during sleep. However, the exact mechanisms behind this were unknown — until now.

      Those among us who grew up with the popular cartoon "Dexter's Laboratory" might remember the famous episode wherein Dexter's trying to learn French overnight. He creates a device that helps him to learn in his sleep by playing French phrases to him. Of course, since the show is a comedy, Dexter's record gets stuck on the phrase "Omelette du fromage" and the next day he's incapable of saying anything else. This is, of course, a problem that puts him through a series of hilarious situations.

      The idea that we can learn in our sleep has captivated the minds of artists and scientists alike; the possibility that one day we could all drastically improve our productivity by learning in our sleep is very appealing. But could such a scenario ever become a reality?

      New research seems to suggest so, and scientists in general are moving closer to understanding precisely what goes on in the brain when we sleep and how the restful state affects learning and memory formation.

      For instance, previous studies have shown that non-rapid eye movement (non-REM) sleep — or dreamless sleep — is crucial for consolidating memories. It has also been shown that sleep spindles, or sudden spikes in oscillatory brain activity that can be seen on an electroencephalogram (EEG) during the second stage of non-REM sleep, are key for this memory consolidation. Scientists were also able to specifically target certain memories and reactivate, or strengthen, them by using auditory cues.

      However, the mechanism behind such achievements remained mysterious until now. Researchers were also unaware if such mechanisms would help with memorizing new information.

      Therefore, a team of researchers set out to investigate. Scott Cairney, from the University of York in the United Kingdom, co-led the research with Bernhard Staresina, who works at the University of Birmingham, also in the U.K. Their findings were published in the journal Current Biology.

      Cairney explains the motivation for the research, saying, "We are quite certain that memories are reactivated in the brain during sleep, but we don't know the neural processes that underpin this phenomenon." "Sleep spindles," he continues, "have been linked to the benefits of sleep for memory in previous research, so we wanted to investigate whether these brain waves mediate reactivation. If they support memory reactivation, we further reasoned that it could be possible to decipher memory signals at the time that these spindles took place."

      To test their hypotheses, Cairney and his colleagues asked 46 participants "to learn associations between words and pictures of objects or scenes before a nap." Afterward, some of the participants took a 90-minute nap, whereas others stayed awake. To those who napped, "Half of the words were [...] replayed during the nap to trigger the reactivation of the newly learned picture memories," explains Cairney.

      "When the participants woke after a good period of sleep," he says, "we presented them again with the words and asked them to recall the object and scene pictures. We found that their memory was better for the pictures that were connected to the words that were presented in sleep, compared to those words that weren't," Cairney reports.

      Using an EEG machine, the researchers were also able to see that playing the associated words to reactivate memories triggered sleep spindles in the participants' brains. More specifically, the EEG sleep spindle patterns "told" the researchers whether the participants were processing memories related to objects or memories related to scenes.

      "Our data suggest that spindles facilitate processing of relevant memory features during sleep and that this process boosts memory consolidation," says Staresina. "While it has been shown previously," he continues, "that targeted memory reactivation can boost memory consolidation during sleep, we now show that sleep spindles might represent the key underlying mechanism."

      Cairney adds, "When you are awake you learn new things, but when you are asleep you refine them, making it easier to retrieve them and apply them correctly when you need them the most. This is important for how we learn but also for how we might help retain healthy brain functions."

      Staresina suggests that this newly gained knowledge could lead to effective strategies for boosting memory while sleeping.

      So, though learning things from scratch à la "Dexter's Lab" may take a while to become a reality, we can safely say that our brains continue to learn while we sleep, and that researchers just got a lot closer to understanding why this happens.

                                From: https://www.medicalnewstoday.com/articles/Mar/2018

A
activation of brain areas not related to memories.
B
the type of brain activity going on: memory of objects or of scenes.
C
a huge net of synapses never registered when a person is sleeping.
D
a type of neuronal activity usually associated with dreams.
1a99e00c-fa
UECE 2018 - Inglês - Interpretação de texto | Reading comprehension

As to the results of the research, the participants who took a nap

                                         T E X T


                          Can you learn in your sleep?


      Sleep is known to be crucial for learning and memory formation. What's more, scientists have even managed to pick out specific memories and consolidate them during sleep. However, the exact mechanisms behind this were unknown — until now.

      Those among us who grew up with the popular cartoon "Dexter's Laboratory" might remember the famous episode wherein Dexter's trying to learn French overnight. He creates a device that helps him to learn in his sleep by playing French phrases to him. Of course, since the show is a comedy, Dexter's record gets stuck on the phrase "Omelette du fromage" and the next day he's incapable of saying anything else. This is, of course, a problem that puts him through a series of hilarious situations.

      The idea that we can learn in our sleep has captivated the minds of artists and scientists alike; the possibility that one day we could all drastically improve our productivity by learning in our sleep is very appealing. But could such a scenario ever become a reality?

      New research seems to suggest so, and scientists in general are moving closer to understanding precisely what goes on in the brain when we sleep and how the restful state affects learning and memory formation.

      For instance, previous studies have shown that non-rapid eye movement (non-REM) sleep — or dreamless sleep — is crucial for consolidating memories. It has also been shown that sleep spindles, or sudden spikes in oscillatory brain activity that can be seen on an electroencephalogram (EEG) during the second stage of non-REM sleep, are key for this memory consolidation. Scientists were also able to specifically target certain memories and reactivate, or strengthen, them by using auditory cues.

      However, the mechanism behind such achievements remained mysterious until now. Researchers were also unaware if such mechanisms would help with memorizing new information.

      Therefore, a team of researchers set out to investigate. Scott Cairney, from the University of York in the United Kingdom, co-led the research with Bernhard Staresina, who works at the University of Birmingham, also in the U.K. Their findings were published in the journal Current Biology.

      Cairney explains the motivation for the research, saying, "We are quite certain that memories are reactivated in the brain during sleep, but we don't know the neural processes that underpin this phenomenon." "Sleep spindles," he continues, "have been linked to the benefits of sleep for memory in previous research, so we wanted to investigate whether these brain waves mediate reactivation. If they support memory reactivation, we further reasoned that it could be possible to decipher memory signals at the time that these spindles took place."

      To test their hypotheses, Cairney and his colleagues asked 46 participants "to learn associations between words and pictures of objects or scenes before a nap." Afterward, some of the participants took a 90-minute nap, whereas others stayed awake. To those who napped, "Half of the words were [...] replayed during the nap to trigger the reactivation of the newly learned picture memories," explains Cairney.

      "When the participants woke after a good period of sleep," he says, "we presented them again with the words and asked them to recall the object and scene pictures. We found that their memory was better for the pictures that were connected to the words that were presented in sleep, compared to those words that weren't," Cairney reports.

      Using an EEG machine, the researchers were also able to see that playing the associated words to reactivate memories triggered sleep spindles in the participants' brains. More specifically, the EEG sleep spindle patterns "told" the researchers whether the participants were processing memories related to objects or memories related to scenes.

      "Our data suggest that spindles facilitate processing of relevant memory features during sleep and that this process boosts memory consolidation," says Staresina. "While it has been shown previously," he continues, "that targeted memory reactivation can boost memory consolidation during sleep, we now show that sleep spindles might represent the key underlying mechanism."

      Cairney adds, "When you are awake you learn new things, but when you are asleep you refine them, making it easier to retrieve them and apply them correctly when you need them the most. This is important for how we learn but also for how we might help retain healthy brain functions."

      Staresina suggests that this newly gained knowledge could lead to effective strategies for boosting memory while sleeping.

      So, though learning things from scratch à la "Dexter's Lab" may take a while to become a reality, we can safely say that our brains continue to learn while we sleep, and that researchers just got a lot closer to understanding why this happens.

                                From: https://www.medicalnewstoday.com/articles/Mar/2018

A
were able to recall all the associations learned before sleeping.
B
memorized more words and associations when they slept for a longer period.
C
had a performance quite similar to those who did not sleep after the presentation of the words.
D
had better memory of the pictures associated with the words replayed in their sleep.
1a923e9b-fa
UECE 2018 - Inglês - Interpretação de texto | Reading comprehension

The new investigation was led by researchers working at

                                         T E X T


                          Can you learn in your sleep?


      Sleep is known to be crucial for learning and memory formation. What's more, scientists have even managed to pick out specific memories and consolidate them during sleep. However, the exact mechanisms behind this were unknown — until now.

      Those among us who grew up with the popular cartoon "Dexter's Laboratory" might remember the famous episode wherein Dexter's trying to learn French overnight. He creates a device that helps him to learn in his sleep by playing French phrases to him. Of course, since the show is a comedy, Dexter's record gets stuck on the phrase "Omelette du fromage" and the next day he's incapable of saying anything else. This is, of course, a problem that puts him through a series of hilarious situations.

      The idea that we can learn in our sleep has captivated the minds of artists and scientists alike; the possibility that one day we could all drastically improve our productivity by learning in our sleep is very appealing. But could such a scenario ever become a reality?

      New research seems to suggest so, and scientists in general are moving closer to understanding precisely what goes on in the brain when we sleep and how the restful state affects learning and memory formation.

      For instance, previous studies have shown that non-rapid eye movement (non-REM) sleep — or dreamless sleep — is crucial for consolidating memories. It has also been shown that sleep spindles, or sudden spikes in oscillatory brain activity that can be seen on an electroencephalogram (EEG) during the second stage of non-REM sleep, are key for this memory consolidation. Scientists were also able to specifically target certain memories and reactivate, or strengthen, them by using auditory cues.

      However, the mechanism behind such achievements remained mysterious until now. Researchers were also unaware if such mechanisms would help with memorizing new information.

      Therefore, a team of researchers set out to investigate. Scott Cairney, from the University of York in the United Kingdom, co-led the research with Bernhard Staresina, who works at the University of Birmingham, also in the U.K. Their findings were published in the journal Current Biology.

      Cairney explains the motivation for the research, saying, "We are quite certain that memories are reactivated in the brain during sleep, but we don't know the neural processes that underpin this phenomenon." "Sleep spindles," he continues, "have been linked to the benefits of sleep for memory in previous research, so we wanted to investigate whether these brain waves mediate reactivation. If they support memory reactivation, we further reasoned that it could be possible to decipher memory signals at the time that these spindles took place."

      To test their hypotheses, Cairney and his colleagues asked 46 participants "to learn associations between words and pictures of objects or scenes before a nap." Afterward, some of the participants took a 90-minute nap, whereas others stayed awake. To those who napped, "Half of the words were [...] replayed during the nap to trigger the reactivation of the newly learned picture memories," explains Cairney.

      "When the participants woke after a good period of sleep," he says, "we presented them again with the words and asked them to recall the object and scene pictures. We found that their memory was better for the pictures that were connected to the words that were presented in sleep, compared to those words that weren't," Cairney reports.

      Using an EEG machine, the researchers were also able to see that playing the associated words to reactivate memories triggered sleep spindles in the participants' brains. More specifically, the EEG sleep spindle patterns "told" the researchers whether the participants were processing memories related to objects or memories related to scenes.

      "Our data suggest that spindles facilitate processing of relevant memory features during sleep and that this process boosts memory consolidation," says Staresina. "While it has been shown previously," he continues, "that targeted memory reactivation can boost memory consolidation during sleep, we now show that sleep spindles might represent the key underlying mechanism."

      Cairney adds, "When you are awake you learn new things, but when you are asleep you refine them, making it easier to retrieve them and apply them correctly when you need them the most. This is important for how we learn but also for how we might help retain healthy brain functions."

      Staresina suggests that this newly gained knowledge could lead to effective strategies for boosting memory while sleeping.

      So, though learning things from scratch à la "Dexter's Lab" may take a while to become a reality, we can safely say that our brains continue to learn while we sleep, and that researchers just got a lot closer to understanding why this happens.

                                From: https://www.medicalnewstoday.com/articles/Mar/2018

A
the University of New York and a team from the University of Birmingham.
B
the University of Birmingham and another university in the UK.
C
two American universities and two other British institutions.
D
a British University and Dexter’s Lab.