Questões Militares Comentadas por alunos

Foram encontradas 80.122 questões

Resolva questões gratuitamente!

Junte-se a mais de 4 milhões de concurseiros!

Q1989746 Inglês

        If styles are general characteristics that differentiate one individual from another, then strategies are those specific “attacks” that we make on a given problem, and that vary considerably within each individual. They are the momentby-moment techniques that we employ to solve “problems” posed by second language input and output. Chamot (2005, p. 112) defines strategies quite broadly as “procedures that facilitate a learning task.”

        Second language acquisition has distinguished between two types of strategy: learning strategies and communication strategies. The former relate to input — to processing, storage, and retrieval, that is, to taking in messages from others. The latter pertain to output, how we productively express meaning, how we deliver messages to others.

(Brown, H.D. Principles of Language Learning and Teaching. 5th ed. White Plains, NY: Addison Wesley Longman, 2006. Adaptado)

No trecho do primeiro parágrafo “and that vary considerably within each individual”, a palavra sublinhada pode ser corretamente substituída por
Alternativas
Q1989744 Inglês

        O termo validade, para referir-se à avaliação de aprendizagem, pode ser definido como o grau pelo qual as notas de um teste nos permitem tirar conclusões em relação ao objetivo do mesmo. Há diversos tipos de validade, dentro os quais destacamos:

        validade de construto – é uma espécie de validade conceitual. Uma avaliação tem validade de construto se pudermos demonstrar que ela mede, exatamente, o construto que deve medir (Hughes, 1989:26). No caso de inglês, poderíamos pensar em habilidades, por exemplo. Dessa forma, uma prova teria validade de construto se medisse a habilidade que deseja medir.

        validade de conteúdo – têm as provas cujo conteúdo apresenta uma quantidade representativa daquilo que tenha sido estudado anteriormente.

FIDALGO, S.S. Livros Didáticos e Avaliação de Aprendizagem: Uma Revisão teórico-Prática. IN: Maria Cristina Damianovic (org). Material Didático: Elaboração e Avaliação. Taubaté: Cabral -Editora e Livraria Universitária. 2007. p. 287-318. Adaptado)

Um teste que obedecesse ao critério “validade” proporia avaliar
Alternativas
Q1989743 Inglês

        O termo validade, para referir-se à avaliação de aprendizagem, pode ser definido como o grau pelo qual as notas de um teste nos permitem tirar conclusões em relação ao objetivo do mesmo. Há diversos tipos de validade, dentro os quais destacamos:

        validade de construto – é uma espécie de validade conceitual. Uma avaliação tem validade de construto se pudermos demonstrar que ela mede, exatamente, o construto que deve medir (Hughes, 1989:26). No caso de inglês, poderíamos pensar em habilidades, por exemplo. Dessa forma, uma prova teria validade de construto se medisse a habilidade que deseja medir.

        validade de conteúdo – têm as provas cujo conteúdo apresenta uma quantidade representativa daquilo que tenha sido estudado anteriormente.

FIDALGO, S.S. Livros Didáticos e Avaliação de Aprendizagem: Uma Revisão teórico-Prática. IN: Maria Cristina Damianovic (org). Material Didático: Elaboração e Avaliação. Taubaté: Cabral -Editora e Livraria Universitária. 2007. p. 287-318. Adaptado)

Concerned with the criterion validity in the design of tests, when preparing an evaluation to your students you would 
Alternativas
Q1989740 Inglês

Multilingualism needs to be understood not so much in terms of separate monolingualisms (adding English to one or more other languages) but rather in much more fluid terms. We can start to think of ELT classrooms in terms of principled polycentrism (Pennycook, 2014). This is not the polycentrism of a World Englishes focus, with its established or fixed norms of regional varieties of English, but a more fluid concept, based on the idea that students are developing complex repertoires of multilingual and multimodal resources. This enables us to think in terms of ELT as developing resourceful speakers who are able to use available language resources and to shift between styles, discourses, registers and genres. This brings the recent sociolinguistic emphasis on repertoires and resources into conversation with a focus on the need to learn how to negotiate and accommodate, rather than to be proficient in one variety of English. So an emerging goal of ELT may be less towards proficient native-speaker-like speakers (which has always been a confused and misguided goal), and to think instead in terms of resourceful speakers (Pennycook, 2012) who can draw on multiple linguistic and semiotic resources.

(Pennycook, A. The Cultural Politics of English as an International Language. London and New York: Routledge. 2017. Adaptado)

In the Brazilian educational context, the view by the author can be translated into
Alternativas
Q1989739 Inglês

Multilingualism needs to be understood not so much in terms of separate monolingualisms (adding English to one or more other languages) but rather in much more fluid terms. We can start to think of ELT classrooms in terms of principled polycentrism (Pennycook, 2014). This is not the polycentrism of a World Englishes focus, with its established or fixed norms of regional varieties of English, but a more fluid concept, based on the idea that students are developing complex repertoires of multilingual and multimodal resources. This enables us to think in terms of ELT as developing resourceful speakers who are able to use available language resources and to shift between styles, discourses, registers and genres. This brings the recent sociolinguistic emphasis on repertoires and resources into conversation with a focus on the need to learn how to negotiate and accommodate, rather than to be proficient in one variety of English. So an emerging goal of ELT may be less towards proficient native-speaker-like speakers (which has always been a confused and misguided goal), and to think instead in terms of resourceful speakers (Pennycook, 2012) who can draw on multiple linguistic and semiotic resources.

(Pennycook, A. The Cultural Politics of English as an International Language. London and New York: Routledge. 2017. Adaptado)

The reading of the excerpt leads us to understand that multilingualism 
Alternativas
Q1989738 Inglês

Leia o desenho animado.

Imagem associada para resolução da questão

Marque a alternativa que contém uma pergunta direta correta:

Alternativas
Q1989737 Inglês

The regional accentism that secretly affects life prospects


        At age 22, Gav Murphy was living outside his home country Wales for the first time, working in his first job in media production in London. His South Wales Valleys accent was very thick, he recalls. He’d say ‘tha’ rather than ‘that’, for instance. He was perfectly understandable; yet a senior colleague overseeing his work insisted Murphy change his accent so all the broadcasters sounded uniform on air. The effects of adaptation were far-reaching. “It sort of broke my brain a little bit,” says Murphy. “I thought about literally every single thing I was saying, literally every time I was saying it. Moving to standard English was just laborious.”


        Foreign-accent discrimination is rampant in professional settings. But discrimination can also extend to certain native speakers of a language, because of the judgements attached to particular accents. While many employers are becoming very sensitive to other types of bias, accent bias remains challenging to root out. But it doesn’t have to be this way.


       While the cognitive shortcuts that contribute to accent bias may be universal, the degree of accent awareness and prejudice varies greatly. For instance, “The UK has a very, very fine-tuned system of accent prestige,” says Devyani Sharma, a sociolinguist at Queen Mary University of London. “It’s a combination of a very monolingual past, where English developed as a symbol of the nation, and the very acute social class hierarchy historically.” She adds that overt accent bias in the US is based more on race, whereas in the UK, it’s more tied to class.


        In some cases, accent bias is directly related to government policy. Since the 1860s, the Japanese government has modernised the country with a focus on Tokyo, says Shigeko Kumagai, a linguist at Shizuoka University, Japan. “Thus, standard Japanese was established based on the speech of educated Tokyoites.” In contrast, the Tohoku dialect spoken in northern Japan became “the most stigmatised dialect in Japan”, says Kumagai. Its image is “rural, rustic, old, stubborn, narrow-minded, backward, poor, uneducated, etc”. Young women from Tohoku are often given discriminatory treatment that makes them feel ashamed of their accents.


        A pesquisa de Kumagai mostra que a forte estereotipagem do dialeto Tohoku é perpetuada pela concentração da indústria de mídia na capital japonesa. De fato, em todo o mundo, a mídia tem um impacto enorme na percepção dos sotaques. Portanto, entendemos por que a preponderância de emissoras do Reino Unido em Londres provavelmente contribuiu para a marginalização do sotaque galês de MurphyKumagai’s research shows that the strong stereotyping of the Tohoku dialect is perpetuated by the concentration of the media industry in the Japanese capital. Indeed, the world over, the media has an enormous impact on perceptions of accents. So we understand why the preponderance of UK broadcasters in London likely contributed to the marginalisation of Murphy’s Welsh accent.


(Christine Ro. www.bbc.com, 08.05.2022. Adaptado)

As a teacher, you wish your students could develop their abilities in critical reading by confronting the content in the text to the reality of Brazilian speakers of Portuguese. You would then provoke them to
Alternativas
Q1989736 Inglês

The regional accentism that secretly affects life prospects


        At age 22, Gav Murphy was living outside his home country Wales for the first time, working in his first job in media production in London. His South Wales Valleys accent was very thick, he recalls. He’d say ‘tha’ rather than ‘that’, for instance. He was perfectly understandable; yet a senior colleague overseeing his work insisted Murphy change his accent so all the broadcasters sounded uniform on air. The effects of adaptation were far-reaching. “It sort of broke my brain a little bit,” says Murphy. “I thought about literally every single thing I was saying, literally every time I was saying it. Moving to standard English was just laborious.”


        Foreign-accent discrimination is rampant in professional settings. But discrimination can also extend to certain native speakers of a language, because of the judgements attached to particular accents. While many employers are becoming very sensitive to other types of bias, accent bias remains challenging to root out. But it doesn’t have to be this way.


       While the cognitive shortcuts that contribute to accent bias may be universal, the degree of accent awareness and prejudice varies greatly. For instance, “The UK has a very, very fine-tuned system of accent prestige,” says Devyani Sharma, a sociolinguist at Queen Mary University of London. “It’s a combination of a very monolingual past, where English developed as a symbol of the nation, and the very acute social class hierarchy historically.” She adds that overt accent bias in the US is based more on race, whereas in the UK, it’s more tied to class.


        In some cases, accent bias is directly related to government policy. Since the 1860s, the Japanese government has modernised the country with a focus on Tokyo, says Shigeko Kumagai, a linguist at Shizuoka University, Japan. “Thus, standard Japanese was established based on the speech of educated Tokyoites.” In contrast, the Tohoku dialect spoken in northern Japan became “the most stigmatised dialect in Japan”, says Kumagai. Its image is “rural, rustic, old, stubborn, narrow-minded, backward, poor, uneducated, etc”. Young women from Tohoku are often given discriminatory treatment that makes them feel ashamed of their accents.


        A pesquisa de Kumagai mostra que a forte estereotipagem do dialeto Tohoku é perpetuada pela concentração da indústria de mídia na capital japonesa. De fato, em todo o mundo, a mídia tem um impacto enorme na percepção dos sotaques. Portanto, entendemos por que a preponderância de emissoras do Reino Unido em Londres provavelmente contribuiu para a marginalização do sotaque galês de MurphyKumagai’s research shows that the strong stereotyping of the Tohoku dialect is perpetuated by the concentration of the media industry in the Japanese capital. Indeed, the world over, the media has an enormous impact on perceptions of accents. So we understand why the preponderance of UK broadcasters in London likely contributed to the marginalisation of Murphy’s Welsh accent.


(Christine Ro. www.bbc.com, 08.05.2022. Adaptado)

The sentence from the fourth paragraph “Young women from Tohoku are often given discriminatory treatment that makes them feel ashamed of their accents” illustrates a particular use of the passive voice in English, one in which the indirect object in the active voice is the subject in the passive sentence. A similar passive construction is found in alternative:
Alternativas
Q1989735 Inglês

The regional accentism that secretly affects life prospects


        At age 22, Gav Murphy was living outside his home country Wales for the first time, working in his first job in media production in London. His South Wales Valleys accent was very thick, he recalls. He’d say ‘tha’ rather than ‘that’, for instance. He was perfectly understandable; yet a senior colleague overseeing his work insisted Murphy change his accent so all the broadcasters sounded uniform on air. The effects of adaptation were far-reaching. “It sort of broke my brain a little bit,” says Murphy. “I thought about literally every single thing I was saying, literally every time I was saying it. Moving to standard English was just laborious.”


        Foreign-accent discrimination is rampant in professional settings. But discrimination can also extend to certain native speakers of a language, because of the judgements attached to particular accents. While many employers are becoming very sensitive to other types of bias, accent bias remains challenging to root out. But it doesn’t have to be this way.


       While the cognitive shortcuts that contribute to accent bias may be universal, the degree of accent awareness and prejudice varies greatly. For instance, “The UK has a very, very fine-tuned system of accent prestige,” says Devyani Sharma, a sociolinguist at Queen Mary University of London. “It’s a combination of a very monolingual past, where English developed as a symbol of the nation, and the very acute social class hierarchy historically.” She adds that overt accent bias in the US is based more on race, whereas in the UK, it’s more tied to class.


        In some cases, accent bias is directly related to government policy. Since the 1860s, the Japanese government has modernised the country with a focus on Tokyo, says Shigeko Kumagai, a linguist at Shizuoka University, Japan. “Thus, standard Japanese was established based on the speech of educated Tokyoites.” In contrast, the Tohoku dialect spoken in northern Japan became “the most stigmatised dialect in Japan”, says Kumagai. Its image is “rural, rustic, old, stubborn, narrow-minded, backward, poor, uneducated, etc”. Young women from Tohoku are often given discriminatory treatment that makes them feel ashamed of their accents.


        A pesquisa de Kumagai mostra que a forte estereotipagem do dialeto Tohoku é perpetuada pela concentração da indústria de mídia na capital japonesa. De fato, em todo o mundo, a mídia tem um impacto enorme na percepção dos sotaques. Portanto, entendemos por que a preponderância de emissoras do Reino Unido em Londres provavelmente contribuiu para a marginalização do sotaque galês de MurphyKumagai’s research shows that the strong stereotyping of the Tohoku dialect is perpetuated by the concentration of the media industry in the Japanese capital. Indeed, the world over, the media has an enormous impact on perceptions of accents. So we understand why the preponderance of UK broadcasters in London likely contributed to the marginalisation of Murphy’s Welsh accent.


(Christine Ro. www.bbc.com, 08.05.2022. Adaptado)

The discourse marker thus, in the sentence from the fourth paragraph “Thus, standard Japanese was established based on the speech of educated Tokyoites.”, is frequently used in English written texts to
Alternativas
Q1989734 Inglês

The regional accentism that secretly affects life prospects


        At age 22, Gav Murphy was living outside his home country Wales for the first time, working in his first job in media production in London. His South Wales Valleys accent was very thick, he recalls. He’d say ‘tha’ rather than ‘that’, for instance. He was perfectly understandable; yet a senior colleague overseeing his work insisted Murphy change his accent so all the broadcasters sounded uniform on air. The effects of adaptation were far-reaching. “It sort of broke my brain a little bit,” says Murphy. “I thought about literally every single thing I was saying, literally every time I was saying it. Moving to standard English was just laborious.”


        Foreign-accent discrimination is rampant in professional settings. But discrimination can also extend to certain native speakers of a language, because of the judgements attached to particular accents. While many employers are becoming very sensitive to other types of bias, accent bias remains challenging to root out. But it doesn’t have to be this way.


       While the cognitive shortcuts that contribute to accent bias may be universal, the degree of accent awareness and prejudice varies greatly. For instance, “The UK has a very, very fine-tuned system of accent prestige,” says Devyani Sharma, a sociolinguist at Queen Mary University of London. “It’s a combination of a very monolingual past, where English developed as a symbol of the nation, and the very acute social class hierarchy historically.” She adds that overt accent bias in the US is based more on race, whereas in the UK, it’s more tied to class.


        In some cases, accent bias is directly related to government policy. Since the 1860s, the Japanese government has modernised the country with a focus on Tokyo, says Shigeko Kumagai, a linguist at Shizuoka University, Japan. “Thus, standard Japanese was established based on the speech of educated Tokyoites.” In contrast, the Tohoku dialect spoken in northern Japan became “the most stigmatised dialect in Japan”, says Kumagai. Its image is “rural, rustic, old, stubborn, narrow-minded, backward, poor, uneducated, etc”. Young women from Tohoku are often given discriminatory treatment that makes them feel ashamed of their accents.


        A pesquisa de Kumagai mostra que a forte estereotipagem do dialeto Tohoku é perpetuada pela concentração da indústria de mídia na capital japonesa. De fato, em todo o mundo, a mídia tem um impacto enorme na percepção dos sotaques. Portanto, entendemos por que a preponderância de emissoras do Reino Unido em Londres provavelmente contribuiu para a marginalização do sotaque galês de MurphyKumagai’s research shows that the strong stereotyping of the Tohoku dialect is perpetuated by the concentration of the media industry in the Japanese capital. Indeed, the world over, the media has an enormous impact on perceptions of accents. So we understand why the preponderance of UK broadcasters in London likely contributed to the marginalisation of Murphy’s Welsh accent.


(Christine Ro. www.bbc.com, 08.05.2022. Adaptado)

The word “standard” is used in the text to refer to
Alternativas
Q1989731 Inglês

The regional accentism that secretly affects life prospects


        At age 22, Gav Murphy was living outside his home country Wales for the first time, working in his first job in media production in London. His South Wales Valleys accent was very thick, he recalls. He’d say ‘tha’ rather than ‘that’, for instance. He was perfectly understandable; yet a senior colleague overseeing his work insisted Murphy change his accent so all the broadcasters sounded uniform on air. The effects of adaptation were far-reaching. “It sort of broke my brain a little bit,” says Murphy. “I thought about literally every single thing I was saying, literally every time I was saying it. Moving to standard English was just laborious.”


        Foreign-accent discrimination is rampant in professional settings. But discrimination can also extend to certain native speakers of a language, because of the judgements attached to particular accents. While many employers are becoming very sensitive to other types of bias, accent bias remains challenging to root out. But it doesn’t have to be this way.


       While the cognitive shortcuts that contribute to accent bias may be universal, the degree of accent awareness and prejudice varies greatly. For instance, “The UK has a very, very fine-tuned system of accent prestige,” says Devyani Sharma, a sociolinguist at Queen Mary University of London. “It’s a combination of a very monolingual past, where English developed as a symbol of the nation, and the very acute social class hierarchy historically.” She adds that overt accent bias in the US is based more on race, whereas in the UK, it’s more tied to class.


        In some cases, accent bias is directly related to government policy. Since the 1860s, the Japanese government has modernised the country with a focus on Tokyo, says Shigeko Kumagai, a linguist at Shizuoka University, Japan. “Thus, standard Japanese was established based on the speech of educated Tokyoites.” In contrast, the Tohoku dialect spoken in northern Japan became “the most stigmatised dialect in Japan”, says Kumagai. Its image is “rural, rustic, old, stubborn, narrow-minded, backward, poor, uneducated, etc”. Young women from Tohoku are often given discriminatory treatment that makes them feel ashamed of their accents.


        A pesquisa de Kumagai mostra que a forte estereotipagem do dialeto Tohoku é perpetuada pela concentração da indústria de mídia na capital japonesa. De fato, em todo o mundo, a mídia tem um impacto enorme na percepção dos sotaques. Portanto, entendemos por que a preponderância de emissoras do Reino Unido em Londres provavelmente contribuiu para a marginalização do sotaque galês de MurphyKumagai’s research shows that the strong stereotyping of the Tohoku dialect is perpetuated by the concentration of the media industry in the Japanese capital. Indeed, the world over, the media has an enormous impact on perceptions of accents. So we understand why the preponderance of UK broadcasters in London likely contributed to the marginalisation of Murphy’s Welsh accent.


(Christine Ro. www.bbc.com, 08.05.2022. Adaptado)

In the context of the second paragraph, the phasal verb “root out” means 
Alternativas
Q1989729 Inglês

The regional accentism that secretly affects life prospects


        At age 22, Gav Murphy was living outside his home country Wales for the first time, working in his first job in media production in London. His South Wales Valleys accent was very thick, he recalls. He’d say ‘tha’ rather than ‘that’, for instance. He was perfectly understandable; yet a senior colleague overseeing his work insisted Murphy change his accent so all the broadcasters sounded uniform on air. The effects of adaptation were far-reaching. “It sort of broke my brain a little bit,” says Murphy. “I thought about literally every single thing I was saying, literally every time I was saying it. Moving to standard English was just laborious.”


        Foreign-accent discrimination is rampant in professional settings. But discrimination can also extend to certain native speakers of a language, because of the judgements attached to particular accents. While many employers are becoming very sensitive to other types of bias, accent bias remains challenging to root out. But it doesn’t have to be this way.


       While the cognitive shortcuts that contribute to accent bias may be universal, the degree of accent awareness and prejudice varies greatly. For instance, “The UK has a very, very fine-tuned system of accent prestige,” says Devyani Sharma, a sociolinguist at Queen Mary University of London. “It’s a combination of a very monolingual past, where English developed as a symbol of the nation, and the very acute social class hierarchy historically.” She adds that overt accent bias in the US is based more on race, whereas in the UK, it’s more tied to class.


        In some cases, accent bias is directly related to government policy. Since the 1860s, the Japanese government has modernised the country with a focus on Tokyo, says Shigeko Kumagai, a linguist at Shizuoka University, Japan. “Thus, standard Japanese was established based on the speech of educated Tokyoites.” In contrast, the Tohoku dialect spoken in northern Japan became “the most stigmatised dialect in Japan”, says Kumagai. Its image is “rural, rustic, old, stubborn, narrow-minded, backward, poor, uneducated, etc”. Young women from Tohoku are often given discriminatory treatment that makes them feel ashamed of their accents.


        A pesquisa de Kumagai mostra que a forte estereotipagem do dialeto Tohoku é perpetuada pela concentração da indústria de mídia na capital japonesa. De fato, em todo o mundo, a mídia tem um impacto enorme na percepção dos sotaques. Portanto, entendemos por que a preponderância de emissoras do Reino Unido em Londres provavelmente contribuiu para a marginalização do sotaque galês de MurphyKumagai’s research shows that the strong stereotyping of the Tohoku dialect is perpetuated by the concentration of the media industry in the Japanese capital. Indeed, the world over, the media has an enormous impact on perceptions of accents. So we understand why the preponderance of UK broadcasters in London likely contributed to the marginalisation of Murphy’s Welsh accent.


(Christine Ro. www.bbc.com, 08.05.2022. Adaptado)

Teaching reading in English is not simply teaching the vocabulary or structures in a text. It means helping students develop reading skills and abilities, as well as establish a purpose for the readings they make.

One important reading ability is reading to grasp the gist of a text. As a teacher, you would then tell your students to go over the article “The regional accentism that secretly affects life prospects” in order to identify its main idea, which is summarized in alternative:

Alternativas
Q1989725 Pedagogia
Os programas de formação inicial e continuada dos profissionais da educação, vinculados às orientações das Diretrizes Curriculares Nacionais Gerais para a Educação Básica (Resolução CNE/CEB nº 04/2010), devem prepará-los para o desempenho de suas atribuições, considerando necessário, de acordo com o artigo 57, § 2º da referida resolução,
Alternativas
Q1989696 Física
Uma nave espacial é enviada para uma hipotética estação a uma velocidade de 0,9 c (c = 300000 m/s). Dentro dela há uma carga de massa 300 kg medida em seu referencial. A viagem até a estação demora 10 meses medidos dentro da nave. A duração da viagem e a massa no referencial da Terra devem ser, em meses e em kg, aproximada e respectivamente,
Alternativas
Q1989694 Física
A difração da luz é um capítulo interessante quando estudado além dos limites da óptica geométrica. Quando um feixe de ondas luminosas planas incide sobre uma placa dotada de uma fenda simples, ocorre o fenômeno da difração que pode ser denominada de difração de Fresnel ou de Fraunhofer. A diferença entre ambas consiste na distância em que um anteparo paralelo é colocado. Se o anteparo estiver
Alternativas
Q1989692 Física
A figura ilustra um sistema óptico em que uma lente esférica convergente L disposta na direção horizontal está presa a um suporte vertical; 30 cm abaixo dela há um anteparo. Um objeto luminoso O, de 10 cm de comprimento, está disposto horizontalmente, preso ao mesmo suporte e a 60 cm acima da lente, próximo ao eixo óptico principal da lente. Sabe-se que a imagem nítida do objeto se forma sobre o anteparo,
Imagem associada para resolução da questão

A distância focal da lente vale -------------- cm, a imagem é ------------ e tem comprimento de ------------ cm.
As lacunas acima estão corretamente preenchidas na alternativa:
Alternativas
Q1989690 Física
Um ventilador elétrico tem, geralmente, três velocidades de rotação. Para cada uma há uma específica corrente elétrica percorrendo o circuito onde se encontra o motor que aciona as pás. Na medida em que se passa de uma velocidade para outra maior,
Alternativas
Q1989689 Física
A figura mostra um circuito em que um gerador de fem 24 V alimenta um circuito ideal com resistores de 2,0 Ω, 2,0 Ω e 3,0 Ω, e um motor de fcem 6,0 V.
Imagem associada para resolução da questão
A potência dissipada pelo motor, em W, deve ser de
Alternativas
Q1989688 Física
Em um ambiente de alto vácuo e constante dielétrica k, considere uma esfera metálica, de raio R, eletrizada uniformemente com carga positiva Q. Das proximidades de sua superfície, uma partícula de massa m e carga positiva q parte do repouso sob ação exclusiva do campo elétrico gerado pela carga Q. Essa partícula deverá passar pelo ponto P, a uma distância d da superfície da esfera, com uma velocidade v. A figura ilustra a situação descrita.
Imagem associada para resolução da questão
A expressão da velocidade v, em função dos dados apresentados, deve ser:
Alternativas
Q1989687 Física
Um aquecedor elétrico de dados nominais (1,0 kW-220 V) é ligado normalmente na rede elétrica e inserido em um frasco adiabático contendo 1,0 L de água (d = 1,0 g/mL: c = 1,0 cal/g.ºC) a 0 ºC em contato com 500 g de gelo (Lfusão = 80 cal/g) a 0 ºC também. O sistema é aquecido até atingir a temperatura de 20 ºC. Considerando a relação de 4 joules para cada caloria, o intervalo de tempo necessário para o sistema atingir tal temperatura deve ser de
Alternativas
Respostas
8981: A
8982: E
8983: C
8984: D
8985: D
8986: E
8987: B
8988: C
8989: B
8990: A
8991: C
8992: E
8993: E
8994: D
8995: C
8996: D
8997: A
8998: B
8999: D
9000: C