Foram encontradas 50 questões.
Nos ensaios de dureza Brinell, um penetrador esférico e duro é forçado contra a superfície do material a ser testado. O índice de dureza Brinell é uma função tanto da magnitude da carga quanto do diâmetro da impressão resultante. Sendo assim, analise.
I. O diâmetro medido pela dureza de Brinell é feito por um microscópio especial de baixa potência, utilizando uma escala gravada na sua ocular.
II. O diâmetro medido é convertido do número HB apropriado com o auxílio de um gráfico; com essa técnica, emprega-se uma ou mais escalas.
III. As cargas utilizadas nos ensaios de dureza Brinell variam entre 500 e 3000 kg, em incrementos de 500 kg.
IV. Durante o ensaio, a carga varia por um tempo específico (entre 10 e 30 s). Os materiais mais duros exigem cargas aplicadas maiores.
Estão corretas apenas as afirmativas
Provas
Os ensaios de dureza Rockwell é o método mais utilizado para medir a dureza, pois é muito simples de executar e não exige qualquer habilidade especial. Diversas escalas diferentes podem ser utilizadas, a partir de combinações possíveis de vários penetradores e diferentes cargas, as quais permitem o ensaio virtualmente de todos os metais e ligas, desde os mais duros até os mais macios. Diante do exposto, analise.
I. Com este sistema, um número de índice de dureza é determinado pela diferença na profundidade de penetração, que resulta da aplicação de uma carga maior seguida por uma carga principal menor.
II. Nos ensaios Rockwell superficiais, a carga é de 10 kg, enquanto as cargas principais são de 60, 100 e 150 kg.
III. Os ensaios Rockwell superficiais são realizados frequentemente para os corpos de prova mais grossos.
IV. Ao se especificar dureza Rockwell e superficial, tanto o número de índice de dureza quanto o símbolo de escala devem ser indicados.
V. O dispositivo para efetuar medição da dureza Rockwell é automatizado e muito simples de usar; a leitura da dureza é direta, e cada medição exige apenas alguns segundos.
Estão corretas apenas as afirmativas
Provas
A dureza é uma medida da resistência do material a uma deformação plástica localizada. Os ensaios de dureza são realizados com mais frequência do que qualquer outro ensaio mecânico, e as durezas medidas são apenas relativas, devendo ser criteriosa a comparação de valores determinados segundo técnicas diferentes. Diante do exposto, assinale a afirmativa INCORRETA.
Provas
“Um cristal metálico sofre um processo de endurecimento quando deformado plasticamente. Esse fenômeno denomina-se encruamento, podendo ser representado numa curva-tensão de ‘cisalhamento versus deformação’ tangencial, onde se observa a elevação da tensão com o aumento da deformação.” De acordo com o trecho anterior, marque V para as afirmativas verdadeiras e F para as falsas.
( ) O agregado policristalino de um metal apresenta taxa de encruamento bem maior do que a de um monocristal do mesmo metal.
( ) O tamanho do grão exerce uma influência marcante no encruamento, alterando a forma e a posição da curva tensão-deformação e, particularmente, o limite de elasticidade.
( ) O encruamento é obtido, nos produtos metálicos, através dos processos de conformação plástica realizados com um trabalho a frio, a uma temperatura comumente ambiente.
( ) Os monocristais de metais de estrutura cúbica encruam através de mecanismo de deslizamento mais simples do que os dos metais de estrutura hexagonal compacta.
( ) Em metais de estrutura hexagonal compacta, o mecanismo de deslizamento ocorre em somente uma família de planos, e o metal apresenta uma pequena taxa de encruamento.
A sequência está correta em
Provas
Nasa successfully tests hypersonic heat shield
July 25, 2012.
The development of a large inflatable heat shield by the Space Technology Program at NASA has a number of implications for the oft-criticized space agency, as successful tests of the technology have led to speculation about its potential to support long-distance travel.
Science Daily reported that the Inflatable Reentry Vehicle Experiment (IRVE-3) was launched from NASA's Wallops Flight Facility on Wallops Island, Virginia. The heat shield reached speeds up to 7,600 miles per hour, successfully, and travelled at this rate for a significant period during the test.
The purpose of the test was to show that a space capsule can rely upon the heat shield to protect itself as it enters an atmosphere, according to the news outlet. Planetary entry and descent, including both a return to Earth from the International Space Station and any prospective missions to Mars, were targeted as potential uses for the outer shell.
“It's great to see the initial results indicate we had a successful test of the hypersonic inflatable aerodynamic decelerator”, James Reuther, deputy director of NASA's Space Technology Program, said in a statement. “This demonstration flight goes a long way toward showing the value of these technologies to serve as atmospheric entry heat shields for future space.”
NASA's engineering research team used a cone of uninflated high-tech rings covered by a thermal blanket of layers of heat resistant materials for IRVE-3, as the heat shield was launched for its suborbital flight from a three-stage Black Brant Rocket, according to Science Daily.
The heat shield was inflated by a system that pumped nitrogen into the aero shell until it expanded to a shape with a diameter of 10 feet. Engineers at the Wallops site monitored IRVE-3 by watching four onboard cameras and onboard instruments, as the temperature and pressure levels of the craft were closely observed to ensure the success of the test.
From takeoff to splashdown, the flight lasted roughly 20 minutes, but the implications of the test could have a far-reaching impact on NASA's ability to support space travel.
“A team of NASA engineers and technicians spent the last three years preparing for the IRVE-3 flight,” said Lesa Roe, director of NASA's Langley Research Center in Hampton, Va. “We are pushing the boundaries with this flight. We look forward to future test launches of even bigger inflatable aero shells.”
Space.com reported that NASA engineers want this test to serve as a springboard for later efforts, including the use of these heat shields for larger payloads, such as ships that contain large amounts of materials or even human passengers.
“We want to go to higher latitudes at that mass, or use this technology for larger payloads, such as humans”, Neal Cheatwood, the principal engineer for the test, told the news outlet
Cheatwood noted that the engineering research team is trying to outline the myriad potential uses for the heat shield, but the first application is likely to be a support role for the removal of garbage for the International Space Station.
Robotic spacecraft are sent to remove trash from the ISS, but can only carry a small amount of supplies on these trips. However, the successful IRVE-3 test showed that there is a potential for the heat shield to increase the productivity of these trips.
“When we send up re-supply [spacecraft] to the station, there's no portable on-demand storage up there,” Cheatwood told Space.com. “When they bring up 'x' number of cubic feet of stuff, we need to get rid of that much as well.”
(http://why.knovel.com/all-engineering-news/1746-nasa-successfully-tests-hypersonic-heat-shield.html – Com adaptações.)
The utterance by Neal Cheatwood “We want to go to higher latitudes at that mass, or use this technology for larger payloads, such as humans” in the indirect speech is
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Nasa successfully tests hypersonic heat shield
July 25, 2012.
The development of a large inflatable heat shield by the Space Technology Program at NASA has a number of implications for the oft-criticized space agency, as successful tests of the technology have led to speculation about its potential to support long-distance travel.
Science Daily reported that the Inflatable Reentry Vehicle Experiment (IRVE-3) was launched from NASA's Wallops Flight Facility on Wallops Island, Virginia. The heat shield reached speeds up to 7,600 miles per hour, successfully, and travelled at this rate for a significant period during the test.
The purpose of the test was to show that a space capsule can rely upon the heat shield to protect itself as it enters an atmosphere, according to the news outlet. Planetary entry and descent, including both a return to Earth from the International Space Station and any prospective missions to Mars, were targeted as potential uses for the outer shell.
“It's great to see the initial results indicate we had a successful test of the hypersonic inflatable aerodynamic decelerator”, James Reuther, deputy director of NASA's Space Technology Program, said in a statement. “This demonstration flight goes a long way toward showing the value of these technologies to serve as atmospheric entry heat shields for future space.”
NASA's engineering research team used a cone of uninflated high-tech rings covered by a thermal blanket of layers of heat resistant materials for IRVE-3, as the heat shield was launched for its suborbital flight from a three-stage Black Brant Rocket, according to Science Daily.
The heat shield was inflated by a system that pumped nitrogen into the aero shell until it expanded to a shape with a diameter of 10 feet. Engineers at the Wallops site monitored IRVE-3 by watching four onboard cameras and onboard instruments, as the temperature and pressure levels of the craft were closely observed to ensure the success of the test.
From takeoff to splashdown, the flight lasted roughly 20 minutes, but the implications of the test could have a far-reaching impact on NASA's ability to support space travel.
“A team of NASA engineers and technicians spent the last three years preparing for the IRVE-3 flight,” said Lesa Roe, director of NASA's Langley Research Center in Hampton, Va. “We are pushing the boundaries with this flight. We look forward to future test launches of even bigger inflatable aero shells.”
Space.com reported that NASA engineers want this test to serve as a springboard for later efforts, including the use of these heat shields for larger payloads, such as ships that contain large amounts of materials or even human passengers.
“We want to go to higher latitudes at that mass, or use this technology for larger payloads, such as humans”, Neal Cheatwood, the principal engineer for the test, told the news outlet
Cheatwood noted that the engineering research team is trying to outline the myriad potential uses for the heat shield, but the first application is likely to be a support role for the removal of garbage for the International Space Station.
Robotic spacecraft are sent to remove trash from the ISS, but can only carry a small amount of supplies on these trips. However, the successful IRVE-3 test showed that there is a potential for the heat shield to increase the productivity of these trips.
“When we send up re-supply [spacecraft] to the station, there's no portable on-demand storage up there,” Cheatwood told Space.com. “When they bring up 'x' number of cubic feet of stuff, we need to get rid of that much as well.”
(http://why.knovel.com/all-engineering-news/1746-nasa-successfully-tests-hypersonic-heat-shield.html – Com adaptações.)
The word highlighted in “The purpose of the test was to show that a space capsule can rely upon the heat shield to protect itself as it enters an atmosphere,…” can be substituted, with no change of meaning, for
Provas
Nasa successfully tests hypersonic heat shield
July 25, 2012.
The development of a large inflatable heat shield by the Space Technology Program at NASA has a number of implications for the oft-criticized space agency, as successful tests of the technology have led to speculation about its potential to support long-distance travel.
Science Daily reported that the Inflatable Reentry Vehicle Experiment (IRVE-3) was launched from NASA's Wallops Flight Facility on Wallops Island, Virginia. The heat shield reached speeds up to 7,600 miles per hour, successfully, and travelled at this rate for a significant period during the test.
The purpose of the test was to show that a space capsule can rely upon the heat shield to protect itself as it enters an atmosphere, according to the news outlet. Planetary entry and descent, including both a return to Earth from the International Space Station and any prospective missions to Mars, were targeted as potential uses for the outer shell.
“It's great to see the initial results indicate we had a successful test of the hypersonic inflatable aerodynamic decelerator”, James Reuther, deputy director of NASA's Space Technology Program, said in a statement. “This demonstration flight goes a long way toward showing the value of these technologies to serve as atmospheric entry heat shields for future space.”
NASA's engineering research team used a cone of uninflated high-tech rings covered by a thermal blanket of layers of heat resistant materials for IRVE-3, as the heat shield was launched for its suborbital flight from a three-stage Black Brant Rocket, according to Science Daily.
The heat shield was inflated by a system that pumped nitrogen into the aero shell until it expanded to a shape with a diameter of 10 feet. Engineers at the Wallops site monitored IRVE-3 by watching four onboard cameras and onboard instruments, as the temperature and pressure levels of the craft were closely observed to ensure the success of the test.
From takeoff to splashdown, the flight lasted roughly 20 minutes, but the implications of the test could have a far-reaching impact on NASA's ability to support space travel.
“A team of NASA engineers and technicians spent the last three years preparing for the IRVE-3 flight,” said Lesa Roe, director of NASA's Langley Research Center in Hampton, Va. “We are pushing the boundaries with this flight. We look forward to future test launches of even bigger inflatable aero shells.”
Space.com reported that NASA engineers want this test to serve as a springboard for later efforts, including the use of these heat shields for larger payloads, such as ships that contain large amounts of materials or even human passengers.
“We want to go to higher latitudes at that mass, or use this technology for larger payloads, such as humans”, Neal Cheatwood, the principal engineer for the test, told the news outlet
Cheatwood noted that the engineering research team is trying to outline the myriad potential uses for the heat shield, but the first application is likely to be a support role for the removal of garbage for the International Space Station.
Robotic spacecraft are sent to remove trash from the ISS, but can only carry a small amount of supplies on these trips. However, the successful IRVE-3 test showed that there is a potential for the heat shield to increase the productivity of these trips.
“When we send up re-supply [spacecraft] to the station, there's no portable on-demand storage up there,” Cheatwood told Space.com. “When they bring up 'x' number of cubic feet of stuff, we need to get rid of that much as well.”
(http://why.knovel.com/all-engineering-news/1746-nasa-successfully-tests-hypersonic-heat-shield.html – Com adaptações.)
If the word “American” and the word “successful” were inserted in the phrase “the heat shield”, the right sequence of words would be
Provas
Nasa successfully tests hypersonic heat shield
July 25, 2012.
The development of a large inflatable heat shield by the Space Technology Program at NASA has a number of implications for the oft-criticized space agency, as successful tests of the technology have led to speculation about its potential to support long-distance travel.
Science Daily reported that the Inflatable Reentry Vehicle Experiment (IRVE-3) was launched from NASA's Wallops Flight Facility on Wallops Island, Virginia. The heat shield reached speeds up to 7,600 miles per hour, successfully, and travelled at this rate for a significant period during the test.
The purpose of the test was to show that a space capsule can rely upon the heat shield to protect itself as it enters an atmosphere, according to the news outlet. Planetary entry and descent, including both a return to Earth from the International Space Station and any prospective missions to Mars, were targeted as potential uses for the outer shell.
“It's great to see the initial results indicate we had a successful test of the hypersonic inflatable aerodynamic decelerator”, James Reuther, deputy director of NASA's Space Technology Program, said in a statement. “This demonstration flight goes a long way toward showing the value of these technologies to serve as atmospheric entry heat shields for future space.”
NASA's engineering research team used a cone of uninflated high-tech rings covered by a thermal blanket of layers of heat resistant materials for IRVE-3, as the heat shield was launched for its suborbital flight from a three-stage Black Brant Rocket, according to Science Daily.
The heat shield was inflated by a system that pumped nitrogen into the aero shell until it expanded to a shape with a diameter of 10 feet. Engineers at the Wallops site monitored IRVE-3 by watching four onboard cameras and onboard instruments, as the temperature and pressure levels of the craft were closely observed to ensure the success of the test.
From takeoff to splashdown, the flight lasted roughly 20 minutes, but the implications of the test could have a far-reaching impact on NASA's ability to support space travel.
“A team of NASA engineers and technicians spent the last three years preparing for the IRVE-3 flight,” said Lesa Roe, director of NASA's Langley Research Center in Hampton, Va. “We are pushing the boundaries with this flight. We look forward to future test launches of even bigger inflatable aero shells.”
Space.com reported that NASA engineers want this test to serve as a springboard for later efforts, including the use of these heat shields for larger payloads, such as ships that contain large amounts of materials or even human passengers.
“We want to go to higher latitudes at that mass, or use this technology for larger payloads, such as humans”, Neal Cheatwood, the principal engineer for the test, told the news outlet
Cheatwood noted that the engineering research team is trying to outline the myriad potential uses for the heat shield, but the first application is likely to be a support role for the removal of garbage for the International Space Station.
Robotic spacecraft are sent to remove trash from the ISS, but can only carry a small amount of supplies on these trips. However, the successful IRVE-3 test showed that there is a potential for the heat shield to increase the productivity of these trips.
“When we send up re-supply [spacecraft] to the station, there's no portable on-demand storage up there,” Cheatwood told Space.com. “When they bring up 'x' number of cubic feet of stuff, we need to get rid of that much as well.”
(http://why.knovel.com/all-engineering-news/1746-nasa-successfully-tests-hypersonic-heat-shield.html – Com adaptações.)
The “ch” in the word technology as in “… the technology have led to...” has the same sound of the word in, EXCEPT,
Provas
Nasa successfully tests hypersonic heat shield
July 25, 2012.
The development of a large inflatable heat shield by the Space Technology Program at NASA has a number of implications for the oft-criticized space agency, as successful tests of the technology have led to speculation about its potential to support long-distance travel.
Science Daily reported that the Inflatable Reentry Vehicle Experiment (IRVE-3) was launched from NASA's Wallops Flight Facility on Wallops Island, Virginia. The heat shield reached speeds up to 7,600 miles per hour, successfully, and travelled at this rate for a significant period during the test.
The purpose of the test was to show that a space capsule can rely upon the heat shield to protect itself as it enters an atmosphere, according to the news outlet. Planetary entry and descent, including both a return to Earth from the International Space Station and any prospective missions to Mars, were targeted as potential uses for the outer shell.
“It's great to see the initial results indicate we had a successful test of the hypersonic inflatable aerodynamic decelerator”, James Reuther, deputy director of NASA's Space Technology Program, said in a statement. “This demonstration flight goes a long way toward showing the value of these technologies to serve as atmospheric entry heat shields for future space.”
NASA's engineering research team used a cone of uninflated high-tech rings covered by a thermal blanket of layers of heat resistant materials for IRVE-3, as the heat shield was launched for its suborbital flight from a three-stage Black Brant Rocket, according to Science Daily.
The heat shield was inflated by a system that pumped nitrogen into the aero shell until it expanded to a shape with a diameter of 10 feet. Engineers at the Wallops site monitored IRVE-3 by watching four onboard cameras and onboard instruments, as the temperature and pressure levels of the craft were closely observed to ensure the success of the test.
From takeoff to splashdown, the flight lasted roughly 20 minutes, but the implications of the test could have a far-reaching impact on NASA's ability to support space travel.
“A team of NASA engineers and technicians spent the last three years preparing for the IRVE-3 flight,” said Lesa Roe, director of NASA's Langley Research Center in Hampton, Va. “We are pushing the boundaries with this flight. We look forward to future test launches of even bigger inflatable aero shells.”
Space.com reported that NASA engineers want this test to serve as a springboard for later efforts, including the use of these heat shields for larger payloads, such as ships that contain large amounts of materials or even human passengers.
“We want to go to higher latitudes at that mass, or use this technology for larger payloads, such as humans”, Neal Cheatwood, the principal engineer for the test, told the news outlet
Cheatwood noted that the engineering research team is trying to outline the myriad potential uses for the heat shield, but the first application is likely to be a support role for the removal of garbage for the International Space Station.
Robotic spacecraft are sent to remove trash from the ISS, but can only carry a small amount of supplies on these trips. However, the successful IRVE-3 test showed that there is a potential for the heat shield to increase the productivity of these trips.
“When we send up re-supply [spacecraft] to the station, there's no portable on-demand storage up there,” Cheatwood told Space.com. “When they bring up 'x' number of cubic feet of stuff, we need to get rid of that much as well.”
(http://why.knovel.com/all-engineering-news/1746-nasa-successfully-tests-hypersonic-heat-shield.html – Com adaptações.)
Match the two columns to classify the “ing forms” and mark the alternative which presents the right sequence.
1. “ing form” used as a verb.
2. “ing form” used as a noun.
3. “ing form” used as an adjective.
( ) “This demonstration flight goes a long way toward showing the value...”
( ) “Engineers at the Wallops site monitored IRVE-3 by watching four onboard cameras…”
( ) “… but the implications of the test could have a far-reaching impact on NASA's ability to support space travel.”
( ) “We are pushing the boundaries with this flight.”
( ) “… the engineering research team is trying to outline the myriad potential uses for the heat shield,…”
Provas
Nasa successfully tests hypersonic heat shield
July 25, 2012.
The development of a large inflatable heat shield by the Space Technology Program at NASA has a number of implications for the oft-criticized space agency, as successful tests of the technology have led to speculation about its potential to support long-distance travel.
Science Daily reported that the Inflatable Reentry Vehicle Experiment (IRVE-3) was launched from NASA's Wallops Flight Facility on Wallops Island, Virginia. The heat shield reached speeds up to 7,600 miles per hour, successfully, and travelled at this rate for a significant period during the test.
The purpose of the test was to show that a space capsule can rely upon the heat shield to protect itself as it enters an atmosphere, according to the news outlet. Planetary entry and descent, including both a return to Earth from the International Space Station and any prospective missions to Mars, were targeted as potential uses for the outer shell.
“It's great to see the initial results indicate we had a successful test of the hypersonic inflatable aerodynamic decelerator”, James Reuther, deputy director of NASA's Space Technology Program, said in a statement. “This demonstration flight goes a long way toward showing the value of these technologies to serve as atmospheric entry heat shields for future space.”
NASA's engineering research team used a cone of uninflated high-tech rings covered by a thermal blanket of layers of heat resistant materials for IRVE-3, as the heat shield was launched for its suborbital flight from a three-stage Black Brant Rocket, according to Science Daily.
The heat shield was inflated by a system that pumped nitrogen into the aero shell until it expanded to a shape with a diameter of 10 feet. Engineers at the Wallops site monitored IRVE-3 by watching four onboard cameras and onboard instruments, as the temperature and pressure levels of the craft were closely observed to ensure the success of the test.
From takeoff to splashdown, the flight lasted roughly 20 minutes, but the implications of the test could have a far-reaching impact on NASA's ability to support space travel.
“A team of NASA engineers and technicians spent the last three years preparing for the IRVE-3 flight,” said Lesa Roe, director of NASA's Langley Research Center in Hampton, Va. “We are pushing the boundaries with this flight. We look forward to future test launches of even bigger inflatable aero shells.”
Space.com reported that NASA engineers want this test to serve as a springboard for later efforts, including the use of these heat shields for larger payloads, such as ships that contain large amounts of materials or even human passengers.
“We want to go to higher latitudes at that mass, or use this technology for larger payloads, such as humans”, Neal Cheatwood, the principal engineer for the test, told the news outlet
Cheatwood noted that the engineering research team is trying to outline the myriad potential uses for the heat shield, but the first application is likely to be a support role for the removal of garbage for the International Space Station.
Robotic spacecraft are sent to remove trash from the ISS, but can only carry a small amount of supplies on these trips. However, the successful IRVE-3 test showed that there is a potential for the heat shield to increase the productivity of these trips.
“When we send up re-supply [spacecraft] to the station, there's no portable on-demand storage up there,” Cheatwood told Space.com. “When they bring up 'x' number of cubic feet of stuff, we need to get rid of that much as well.”
(http://why.knovel.com/all-engineering-news/1746-nasa-successfully-tests-hypersonic-heat-shield.html – Com adaptações.)
In the sentence “… successful tests of the technology have led to speculation about its potential…”, the Present Perfect was used to express the idea of an action that
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