Considerando condições ambientes, assinale a opção ERRADA.

Considere que 20 g de tiossulfato de potássio com pureza de 95% reagem com ácido clorídrico em excesso, formando 3,2 g de um sólido de coloração amarela. Assinale a alternativa que melhor representa o rendimento desta reação.

Texto 1

Vou confessar um pecado: às vezes, faço maldades. Mas não faço por mal. Faço o que faziam os mestres zen com seus "koans". "Koans" eram rasteiras que os mestres passavam no pensamento dos discípulos. Eles sabiam que só se aprende o novo quando as certezas velhas caem. E acontece que eu gosto de passar rasteiras em certezas de jovens e de velhos...

Pois o que eu faço é o seguinte. Lá estão os jovens nos semáforos, de cabeças raspadas e caras pintadas, na maior alegria, celebrando o fato de haverem passado no vestibular. Estão pedindo dinheiro para a festa! Eu paro o carro, abro a janela e na maior seriedade digo: "Não vou dar dinheiro. Mas vou dar um conselho. Sou professor emérito da Unicamp. O conselho é este: salvem-se enquanto é tempo!". Aí o sinal fica verde e eu continuo.

"Mas que desmancha-prazeres você é!", vocês me dirão. É verdade. Desmancha-prazeres. Prazeres inocentes baseados no engano. Porque aquela alegria toda se deve precisamente a isto: eles estão enganados.

Estão alegres porque acreditam que a universidade é a chave do mundo. Acabaram de chegar ao último patamar. As celebrações têm o mesmo sentido que os eventos iniciáticos – nas culturas ditas primitivas, as provas a que têm de se submeter os jovens que passaram pela puberdade. Passadas as provas e os seus sofrimentos, os jovens deixaram de ser crianças. Agora são adultos, com todos os seus direitos e deveres. Podem assentar-se na roda dos homens. Assim como os nossos jovens agora podem dizer: "Deixei o cursinho. Estou na universidade".

Houve um tempo em que as celebrações eram justas. Isso foi há muito tempo, quando eu era jovem. Naqueles tempos, um diploma universitário era garantia de trabalho. Os pais se davam como prontos para morrer quando uma destas coisas acontecia: 1) a filha se casava. Isso garantia o seu sustento pelo resto da vida; 2) a filha tirava o diploma de normalista. Isso garantiria o seu sustento caso não casasse; 3) o filho entrava para o Banco do Brasil; 4) o filho tirava diploma.

O diploma era mais que garantia de emprego. Era um atestado de nobreza. Quem tirava diploma não precisava trabalhar com as mãos, como os mecânicos, pedreiros e carpinteiros, que tinham mãos rudes e sujas.

Para provar para todo mundo que não trabalhavam com as mãos, os diplomados tratavam de pôr no dedo um anel com pedra colorida. Havia pedras para todas as profissões: médicos, advogados, músicos, engenheiros. Até os bispos tinham suas pedras.

(Ah! Ia me esquecendo: os pais também se davam como prontos para morrer quando o filho entrava para o seminário para ser padre – aos 45 anos seria bispo – ou para o exército para ser oficial – aos 45 anos seria general.)

Essa ilusão continua a morar na cabeça dos pais e é introduzida na cabeça dos filhos desde pequenos. Profissão honrosa é profissão que tem diploma universitário. Profissão rendosa é a que tem diploma universitário. Cria-se, então, a fantasia de que as únicas opções de profissão são aquelas oferecidas pelas universidades.

Quando se pergunta a um jovem "O que é que você vai fazer?", o sentido dessa pergunta é "Quando você for preencher os formulários do vestibular, qual das opções oferecidas você vai escolher?". E as opções não oferecidas? Haverá alternativas de trabalho que não se encontram nos formulários de vestibular?

Como todos os pais querem que seus filhos entrem na universidade e (quase) todos os jovens querem entrar na universidade, configura-se um mercado imenso, mas imenso mesmo, de pessoas desejosas de diplomas e prontas a pagar o preço. Enquanto houver jovens que não passam nos vestibulares das universidades do Estado, haverá mercado para a criação de universidades particulares. É um bom negócio.

Alegria na entrada. Tristeza ao sair. Forma-se, então, a multidão de jovens com diploma na mão, mas que não conseguem arranjar emprego. Por uma razão aritmética: o número de diplomados é muitas vezes maior que o número de empregos.

Já sugeri que os jovens que entram na universidade deveriam aprender, junto com o curso "nobre" que frequentam, um ofício: marceneiro, mecânico, cozinheiro, jardineiro, técnico de computador, eletricista, encanador, descupinizador, motorista de trator... O rol de ofícios possíveis é imenso. Pena que, nas escolas, as crianças e os jovens não sejam informados sobre essas alternativas, por vezes mais felizes e mais rendosas.

Tive um amigo professor que foi guindado, contra a sua vontade, à posição de reitor de um grande colégio americano no interior de Minas. Ele odiava essa posição porque era obrigado a fazer discursos. E ele tremia de medo de fazer discursos. Um dia ele desapareceu sem explicações. Voltou com a família para o seu país, os Estados Unidos. Tempos depois, encontrei um amigo comum e perguntei: "Como vai o Fulano?". Respondeu-me: "Felicíssimo. É motorista de um caminhão gigantesco que cruza o país!".

(Rubem Alves. Diploma não é solução, Folha de S. Paulo, 25/05/2004.)

De acordo com o autor,

Teflon was Invented by Accident

Today I found out Teflon was invented by accident.

The man who accidentally invented it was Dr. Roy Plunkett. After receiving his BA, MS, and eventually PhD in organic chemistry, Dr. Plunkett took a job with DuPont, in Jackson New Jersey. He was subsequently assigned to work on synthesizing various new forms of refrigerant, trying to find a non-toxic alternative to refrigerants like sulfur dioxide and ammonia.

According to DuPont, in 1938, 27 year old Dr. Plunkett and his assistant, Jack Rebok, were experimenting with one such potential alternative refrigerant, tetrafluorethylene (TFE). Dr. Plunkett subsequently created around 100 pounds of TFE and stored the gas in small cylinders.

On April 6, 1938, upon opening the valve on one of the pressurized cylinders of TFE that had previously been frozen, nothing came out, even though by its weight, it seemed to still be full. Dr. Plunkett and Jack Rebok then decided to investigate further by cutting the cylinder open. Once they managed to get it open, they discovered that the TFE gas inside had polymerized into a waxy white powder, polytetrafluoroethylene (PTFE) resin.

Ever the scientist, Plunkett then proceeded to run tests on this new substance to see if it had any unique or useful properties. Four of the most important properties of this substance discovered were that it was extremely slippery (one of the slipperiest substances known to man), non-corrosive, chemically stable, and that it had an extremely high melting point. These properties were deemed interesting enough that the study of the substance was transferred to DuPont’s Central Research Department and assigned to chemists that had special experience in polymer research and development, while Dr. Plunkett was then promoted and transferred to a separate division that produced tetraethyl (sic), used to boost gasoline octane levels.

Three years later, the process and name of Teflon were patented and trademarked. Four years after that, Teflon first began being sold, initially only used for various industrial and military applications due to the expense of producing TFE. By the 1960s, various forms of Teflon were being used in a variety of applications, such as stain repellant in fabrics and electrical wire insulation. It was also in the 1960s that Teflon began being used in its most publicly known application, as a coating for non-stick pans. Today, Teflon or other brands of the same product are also used in windshield wipers; carpets and furniture (as a stain repellant); light bulbs; coating on glasses; in various hair products; in semiconductor manufacturing; automotive lubricant; igniters for solid-fuel rocket propellants; and in infrared decoy flares, among other things.

Adaptado de www.todayIfoundout.com (acesso em 19/07/2015).

Uma bobina metálica circular de raio !$ r !$, com !$ N !$ espiras e resistência elétrica !$ R\ !$, é atravessada por um campo de indução magnética de intensidade !$ B !$. Se o raio da bobina é aumentado de uma fração !$ Δ r \ll r !$, num intervalo de tempo !$ Δ t !$, e desconsiderando as perdas, a máxima corrente induzida será de

Enquanto em repouso relativo a uma estrela, um astronauta vê a luz dela como predominantemente vermelha, de comprimento de onda próximo a 600 nm. Acelerando sua nave na direção da estrela, a luz será vista como predominantemente violeta, de comprimento de onda próximo a 400 nm, ocasião em que a razão da velocidade da nave em relação à da luz será de

Um pêndulo simples é composto por uma massa presa a um fio metálico de peso desprezível. A figura registra medidas do tempo !$ T !$ em segundos, para 10 oscilações completas e seguidas do pêndulo ocorridas ao longo das horas do dia, !$ t !$. Considerando que neste dia houve uma variação térmica total de 20°C, assinale o valor do coeficiente de dilatação térmica do fio deste pêndulo.

Três barras de peso desprezível, articuladas nos pinos !$ P,Q !$ e !$ R\ !$, constituem uma estrutura vertical em forma de triângulo isósceles, com 6,0 m de base e 4,0 m de altura, que sustenta uma massa !$ M !$ suspensa em !$ Q !$ em equilíbrio estático. O pino !$ P !$ também é articulado no seu apoio fixo, e o pino !$ R\ !$ apoia-se verticalmente sobre o rolete livre. Sendo de !$ 1,5 × 10^4 N !$ e !$ 5,0 × 10^3 N !$ os respectivos valores máximos das forças de tração e compressão suportáveis por qualquer das barras, o máximo valor possível para !$ M !$ é de

Brazil’s business Belindia – Why the country produces fewer world-class companies than it should

BRAZILIANS make up almost 3% of the planet’s population and produce about 3% of its output. Yet of the firms in Fortune magazine’s 2014 “Global 500” ranking of the biggest companies by revenue only seven, or 1.4%, were from Brazil, down from eight in 2013. And on Forbes’s list of the 2,000 most highly valued firms worldwide just 25, or 1.3%, were Brazilian. The country’s biggest corporate “star”, Petrobras, is mired in scandals, its debt downgraded to junk status. In 1974 Edmar Bacha, an economist, described its economy as “Belindia”, a Belgium-sized island of prosperity in a sea of India-like poverty. Since then Brazil has done far better than India in alleviating poverty, but in business terms it still has a Belindia problem: a handful of world-class enterprises in a sea of poorly run ones.

Brazilian businesses face a litany of obstacles: bureaucracy, complex tax rules, shoddy infrastructure and a shortage of skilled workers—to say nothing of a stagnant economy. But a big reason for Brazilian firms’ underperformance is less well rehearsed: poor management. Since 2004 John van Reenen of the London School of Economics and his colleagues have surveyed 11,300 midsized firms in 34 countries, grading them on a five-point scale based on how well they monitor their operations, set targets and reward performance. Brazilian firms’ average score, at 2.7, is similar to that of China’s and a bit above that of India’s. But Brazil ranks below Chile (2.8) and Mexico (2.9); America leads the pack with 3.3. The best Brazilian firms score as well as the best American ones, but its long tail of badly run ones is fatter.

Part of the explanation is that medium and large firms tend to be better-organised than small ones, and not only because well-run ones are likelier to grow. Brazil offers incentives aplenty to stay bitty, such as preferential tax treatment for firms with a turnover of no more than 3.6m reais ($1.3m). As they expand, many firms split rather than face increased scrutiny from the taxman. According to the World Bank, a midsized Brazilian firm spends 2,600 hours filing taxes each year. In Mexico, it is 330 hours.

Ownership patterns play a part too. Many Brazilian concerns are controlled by an individual shareholder, or one or two families. Two-thirds of those with sales of more than $1 billion a year are family-owned, notes Heinz-Peter Elstrodt of McKinsey, a consulting firm. That is less than in Mexico (96%) or South Korea (84%) but more than in America or Europe. Mr Van Reenen’s research shows that where family owners plump for outside chief executives, their firms do no worse than similarly sized ones with more diverse shareholders. But all too often they pick kin over professional managers—and performance suffers. This is particularly true in “low-trust” societies like Brazil, where bosses hire relatives instead of better-qualified strangers to avoid being robbed or sued for falling foul of overly worker-friendly labour laws.

Decades of economic turmoil—which ended when hyperinflation was vanquished in 1994—meant that companies were managed from crisis to crisis. This forced Brazilian firms to be nimble. But it also encouraged short-termism, which management consultants and academics finger as Brazilian managers’ number-one sin. Faced with a record drought in 2014, and a subsequent spike in energy prices in a hydropower-dependent country, Usiminas, a steelmaker, stopped smelting and started selling power it had bought on cheap long-term contracts. Energy sales made up most of its operating profits that year. Such short-term stunts are hardly the path to long-term greatness.

Worse, crisis management all too often consists of going cap in hand to the government. Brazilian bosses continue to waste hours in meetings with politicians that could be better spent improving their businesses. In January 2014, as vehicle sales flagged, the automotive industry’s reflex reaction was to descend on the capital, Brasília, and demand an extension of its costly tax breaks. Thanks to lifelines cast by the state, feeble firms stay afloat rather than sink and make room for more agile competitors. Shielded from competition by tariffs, subsidies and local-content rules, they have little reason to innovate. A locally invented gizmo which lets cars run on both petrol and biodiesel is nifty. But, asks Marcos Lisboa of Insper, a business school, does that really justify six decades of public support for the motor industry?

The dead hand of government

Indeed, a glance at the “Belgian” end of Brazil’s corporate landscape suggests that successful firms cluster in sectors the state has not tried desperately to help, such as retail or finance. Bradesco, a big lender, is internationally praised as a pioneer of automated banking. Each month Arezzo creates 1,000 new models of women’s shoes, and picks 170-odd to sell in its shops.

Brazil’s other world-beaters are in industries like agriculture and aerospace, which are free to compete at home and abroad, and in which the government sticks to its proper role. In 1990 farms were allowed to consolidate and to buy foreign machines, pesticides and fertiliser. Efforts by Brazil’s trade negotiators opened up export markets. JBS, a meat giant, can slaughter 100,000 head of cattle a day, selling more beef than any rival worldwide. Thanks in part to Embrapa, the national agriculture-research agency, Brazilian farms have been raising productivity by about 4% a year for two decades. Similarly, a supply of skilled engineers and know-how from the government’s Technological Institute of Aeronautics has helped turn Embraer, privatised in 1994, into one of the world’s most successful aircraft-makers.

The success of businesses such as these offers a lesson for the state. The best way to make Brazil’s underperforming firms more competitive would be to make them compete more. Coddling by the state can be more a curse than a blessing. Ronald Reagan’s dictum that the nine most terrifying words in the English language are, “I’m from the government and I’m here to help,” translates well into Flemish, Hindi and Brazilian Portuguese.

By Schumpeter. In: The Economist. Feb 28th,2015.

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Your Facial Bone Structure Has a Big Influence on How People See You

(…) Selfies, headshots, mug shots — photos of oneself convey more these days than snapshots ever did back in the Kodak era. Most digitally minded people continually post and update pictures of themselves at professional, social media and dating sites such as LinkedIn, Facebook, Match.com and Tinder. For better or worse, viewers then tend to make snap judgments about someone’s personality or character from a single shot. As such, it can be a stressful task to select the photo that conveys the best impression of ourselves. For those of us seeking to appear friendly and trustworthy to others, a new study underscores an old, chipper piece of advice: Put on a happy face.

A newly published series of experiments by cognitive neuroscientists at New York University is reinforcing the relevance of facial expressions to perceptions of characteristics such as trustworthiness and friendliness. More importantly, the research also revealed the unexpected finding that perceptions of abilities such as physical strength are not dependent on facial expressions but rather on facial bone structure.

The team’s first experiment featured photographs of 10 different people presenting five different facial expressions each. Study subjects rated how friendly, trustworthy or strong the person in each photo appeared. A separate group of subjects scored each face on an emotional scale from “very angry” to “very happy.” And three experts not involved in either of the previous two ratings to avoid confounding results calculated the facial width-to-height ratio for each face. An analysis revealed that participants generally ranked people with a happy expression as friendly and trustworthy but not those with angry expressions. Surprisingly, participants did not rank faces as indicative of physical strength based on facial expression but graded faces that were very broad as that of a strong individual.

In a second survey facial expression and facial structure were manipulated in computer-generated faces. Participants rated each face for the same traits as in the first survey, with the addition of a rating for warmth. Again, people thought a happy expression, but not an angry one, indicated friendliness, trustworthiness — and in this case, warmth. The researchers then showed two additional sets of participants the same faces, this time either with areas relevant to facial expressions obscured or the width cropped. In the first variation, for faces lacking emotional cues, people could no longer perceive personality traits but could still perceive strength based on width. Similarly, for those faces lacking structural cues, people could no longer perceive strength but could still perceive personality traits based on facial expressions.

In a third iteration of the survey participants had to pick four faces out of a lineup of eight faces varied for expression and width that they might select either as their financial advisor or as the winner of a power-lifting competition. As might be expected, participants picked faces with happier expressions as financial advisors and selected broader faces as belonging to power-lifting champs.

In a final survey the researchers generated more than 100 variations of one individual “base face” by varying facial features. Participants saw two faces at a time, and then picked one as either trustworthy or high in ability or as a good financial advisor or power-lifting winner. Using these results, a computer then created an average face for each of these four categories, which were shown to a separate set of participants who had to pick which face appeared either more trustworthy or stronger. Most of the participants found the computer-generated averages to be good representations of trustworthiness or strength — and generally saw the average “financial advisor” face as more trustworthy and the “powerlifter” face as stronger. The findings from all four surveys were published in the Personality and Social Psychology Bulletin on June 18.

Adaptado de www.scientific.american.com/article/your-facial-bone-strecture-has-a-big-influence-on-how-people-see-you.(acesso em 20/8/2015)