(ENEM 2017 LIBRAS)
Pertencente ao Romantismo, a obra de Victor Meirelles caracteriza-se como uma
Questões relacionadas
- Língua Inglesa | 2.05 Adjetivos
(PUC-RIO) Driverless automobiles - The car that parks itself
CARS that need no driver are just around the corner according to researchers who have been testing vehicles bristling with aerials and cameras on public roads in America. However, researchers do not make cars, so it will be up to firms that do to bring the technology to market. And carmakers are a conservative bunch. Still, slowly and steadily the autonomous car will arrive, with the help of an increasing number of automated driving aids. A Swedish carmaker has recently demonstrated one such feature: a car that really does park itself.
Some cars already have systems that assist with parking, but these are not completely autonomous. They can identify an empty parallel-parking space and steer into it while the driver uses the brake. The Swedish system, however, lets the driver get out and use a smartphone application to instruct the vehicle to park. The car then 1trundles off, manoeuvres into a parking place and sends a message to the driver to inform him where it is. The driver can collect the car in person or use his phone to call it back to where he dropped it off. Autonomous parking could thus be provided at places like shopping centers and airports, which are controlled areas in which automated vehicles can be managed more easily than on open highways. In the past, designs for doing this have relied on car parks being fitted with buried guide wires that a vehicle can follow to an empty bay. That, though, creates 2a chicken-and-egg problem: car-park operators will not invest in such infrastructure until there is a sufficient number of suitably equipped cars on the road. Drivers, conversely, will not want to buy self-parking cars if there is nowhere to use them.
This means, as a safety engineer working on the project observes, that for autonomous parking to work most of the technology will have to be in the car itself. The test car, which looks like a normal car, therefore uses on-board GPS mapping, cameras with image-recognition software, and radar sensors to find its own way around a car park and avoid pedestrians and non-autonomous vehicles. The same engineer says the system is five to ten years from commercial deployment. If it proves a success then infrastructure might adapt to it, for instance by packing cars into tighter spaces. If there is no one in them there is no need to make room for their doors to open.
Driverless cars would also need to communicate with one another, to enhance safety. That, too, is coming. 3A number of carmakers are developing wireless networking systems through which vehicles can exchange data, such as their speed, their steering angle and even their weight, to forewarn anti-collision systems and safety devices if an accident looks likely.
In the USA, for example, a carmaker recently tested a brake light that can provide an early warning to other motorists. If the brakes are applied hard in an emergency, a signal is broadcast. This illuminates a warning light in the dashboard of suitably equipped following vehicles, even if they are out of sight around a bend or not immediately behind the vehicle doing the braking.
The American company has been testing this system as part of a collaborative research project with several European carmakers. 4They have put a fleet of 150 experimental vehicles on the roads. When they tested a group of these, the Americans found the technology let drivers brake much earlier, helping avoid collisions. A driverless car would be able to react even faster.
Another member of the research group has been testing driverless cars on roads around Munich— including belting down some of Germany’s high-speed autobahns. 5The ordinary-looking models use a variety of self-contained guidance systems. These include cameras mounted on the upper windscreen, which can identify road markings, signs and various obstacles likely to be encountered on roads.
The German cars also use a radar, to gauge how far the vehicle is from other cars and potential obstacles, and a lidar, which works like a radar but at optical frequencies. The lidar employs laser beams to scan the road ahead and builds up from the reflections a three-dimensional image of what this looks like. The image is processed by a computer in the vehicle, which also collects and compares data from a high-accuracy GPS unit. A series of ultrasonic sonars similar to those used in vehicles to provide parking assistance are placed around the car to add to the virtual picture. And just to make sure, a set of accelerometers provide an inertial navigation system that double-checks the vehicle’s position on the road.
6Although these cars can be switched to an autonomous driving mode, they are still required to have someone in the driving seat who can take over in the event of any difficulty. Some cars can steer themselves, slow down, brake and accelerate, even changing lanes to overtake slower vehicles.From the print edition: Science and Technology Jun 29th 2013
The author uses the phrasal verb “trundles off” (ref. 1) that could be replaced by:
- Geografia | 3.7 Impactos Ambientais
(FUVEST 2017 1° FASE) Leia o texto e observe a ilustração.
O Programa de Despoluição da Baía de Guanabara – PDBG – foi concebido para melhorar as condições sanitárias e ambientais da Região Metropolitana do Rio de Janeiro. Verifique a distribuição, a situação e as fases de operação das Estações de Tratamento de Esgoto (ETEs) do PDBG.
Considerando essas informações, é correto afirmar:
- Química | 1.3 Classificação Periódica
O mineral mais explorado no Brasil é o minério de ferro bruto hematita (Fe2O3), a magnetita (Fe3O4), a limonita (Fe2O3 . H2O) e a siderita (FeCO3). Os sulfetos de ferro, como é o caso da pirita (FeS2), possuem grande importância econômica mundial porque são matérias-primas básicas do aço (liga) utilizado nas estruturas de indústrias, edifícios, hotéis, estádios, aeroportos, pontes e shoppings, além de inúmeros outros usos. Podemos dizer que nos minérios de ferro, além do elemento químico ferro tem os:
- Química | 3.6 Reações Orgânicas
(FUVEST) Em um laboratório químico, foi encontrado um frasco de vidro contendo um líquido incolor e que apresentava o seguinte rótulo:
Composto Alfa : C7H8O
Para identificar a substância contida no fraco, foram feitos os seguintes testes:
I. Dissolveram-se alguns mililitros do líquido do frasco em água, resultando uma solução neutra. A essa solução, adicionaram-se uma gota de ácido e uma pequena quantidade de um forte oxidante. Verificou-se a formação de um composto branco insolúvel em água fria, mas solúvel em água quente. A solução desse composto em água quente apresentou pH = 4.
II. O sólido branco, obtido no teste anterior, foi dissolvido em etanol e a solução foi aquecida na presença de um catalisador. Essa reação produziu benzoato de etila, que é um éster aromático, de fórmula C9H10O2.
Com base nos resultados desses testes, concluiu-se que o Composto Alfa é:
- Biologia | 15.1 Ideias Evolutivas
(G1 - cftsc) Em 2009, comemorou-se o bicentenário de nascimento do naturalista Charles Darwin
(1809-1882), assim como os 150 anos de publicação da sua obra Origem das espécies (1859). Charles Darwin, assim como diversos outros naturalistas e pesquisadores contribuíram para o entendimento atual da evolução biológica. No mesmo ano de nascimento de Darwin, Jean Baptiste Lamarck (1744-1829) publicou sua obra Filosofia Zoológica, na qual defende as hipóteses do uso e desuso e da transmissão hereditária dos caracteres adquiridos.
Disponível em: cienciahoje.uol.com.br/135496. Acesso em: 6 set. 2009 (Adaptado).
Com base no texto acima, nas teorias de evolução das espécies e nos princípios genéticos relacionados, assinale a alternativa incorreta.