Questões - AFA | Gabarito e resoluções

(AFA - 2018) TEXTO PARA A PRXIMA QUESTO. FOOD SHORTAGE CAUSES, EFFECTS AND SOLUTIONS Food shortage is a serious problem facing the world and is prevalent in sub-Saharan Africa. The scarcity of food is caused by economic, environmental and social factors such as crop failure, overpopulation [5] and poor government policies are the main cause of food scarcity in most countries. Environmental factors determine the kind of crops to be produced in a given place, economic factors determine the buying and production capacity and socio-political factors determine [10] distribution of food to the masses. Food shortage has far reaching long and short term negative impacts which include starvation, malnutrition, increased mortality and political unrest1. There is need to collectively address the issue of food insecurity using both emergency and long [15] term measures. Causes of food shortages There are a number of social factors causing food shortages. The rate of population increase is higher than increase in food production. The world is consuming [20] more than it is producing, leading to decline in food stock and storage level and increased food prices due to soaring2 demand. Increased population has led to clearing of agricultural land for human settlement reducing agricultural production (Kamdor, 2007). [25] Overcrowding of population in a given place results in urbanization of previously rich agricultural fields. Destruction of forests for human settlement, particularly tropical rain forest has led to climatic changes, such as prolonged droughts and desertification. Population [30] increase means more pollution as people use more fuel in cars, industry, domestic cooking. The resultant effect is increased air and water pollution which affect the climate and food production. Environmental factors have greatly contributed [35]to food shortage. Climatic change has reduced agricultural production. The change in climate is majorly caused by human activities and to some small extent natural activities. Increased combustion of fossil fuels due to increasing population through power plant, motor [40] transport and mining of coal and oil emits green house gases which have continued to affect world climate. Deforestation of tropical forest due to human pressure has changed climatic patterns and rainfall seasons, and led to desertification which cannot support a crop [45] production. Land degradation due to increased human activities has impacted negatively on agricultural production (Kamdor, 2007). Natural disasters such as floods, tropical storms and prolonged droughts are on the increase and have devastating impacts on food security [50] particularly in developing countries. There are several economic factors that contribute to food shortage. Economic factors affect the ability of farmers to engage in agricultural production. Poverty situation in developing nations have reduced their capacity to produce food, as [55] most farmers cannot afford seed and fertilizers. They use poor farming methods that cannot yield3 enough, even substantial use. Investments in agricultural research and developing are very low in developing nations. Recent global financial crisis have led to increase in food prices [60] and reduced investments in agriculture by individuals and governments in developed nations resulting in reduced food production. Effects of food shortage There are a number of short term effects of food shortage. [65] The impact on children, mothers and elderly are very evident as seen in malnutrition and hunger related deaths. Children succumb to hunger within short period as they cannot stand long period of starvation and they die even before the arrival of emergency [70] assistance. There are also long term effects of food shortage. These include increase in the price of food as a result demand and supply forces. Increasing cost of food production due to the increase in fuel prices coupled [75]with persistent drought in grain producing regions has contributed to the increase in the price of food in the world. Increase in oil price led to increase in the price of fertilizers, transportation of food and also industrial agriculture. Increasing food prices culminated in political [80] instability and social unrest in several nations across the globe in 2007, in countries of Mexico, Cameroon, Brazil, Burkina Faso, Pakistan, Egypt and Bangladesh among other nations (Kamdor, 2007). Solution to problem of food shortage [85] There are some solutions to the problem of food shortage. There is need to reduce production of carbon emissions and pollution to reduce the resultant climatic change through concerted and individual efforts. There is need to invest in clean energy such as solar, nuclear, [90] and geothermal power in homes and industries, because they dont have adverse effects on the environment (Kamdor, 2007). Rich nations should help poor nations to develop and use clean and renewable energy in order to stabilize green house emissions into the atmosphere [95] (Watson, nd). Government need to work in consultation with climatic bodies, World Bank and the UN to engage in projects aimed at promoting green environment. Conclusion Causes of food shortage are well known and [100] can be solved if appropriate measures to solve the problem are taken and effectively implemented. Environmental causes of food shortages are changes in climatic and pollution due to human activities such overgrazing4 and deforestation which can be controlled [105] through legislation. (Adapted from http://www.paypervids.com/food-shortage-causes- effects-solutions/Acesso em:14 fev 2017) *os nmeros entre colchetes indicam os nmeros das linhas do texto original. Glossary: 1. unrest disagreement or fighting between different groups of people 2. soaring something that increases rapidly above the usual level 3. yield to supply or produce something such as profit or an amount or food 4. overgrazing excessive use of land where animals feed on grass Some environmental factors that have contributed to food shortage are

Questão 64

QUESTO ANULADA (AFA - 2018) A tecnologia dominante nos controles remotos de televisores (TV) o infravermelho (IV). A premissa bsica do funcionamento de um controle remoto IV o uso da luz para levar sinais entre um controle remoto e o aparelho que ele controla. Assim, o controle da TV apenas um gerador de IV, tendo cada boto uma frequncia diferente, e ento, de acordo com a frequncia recebida pela TV, ela interpreta como sendo um comando (exemplo: trocar de canal). Considerando que o comprimento de onda do IV utilizado nos controles remotos de TV varia de 750 nm a 1.000m, aenergia carregada por um fton na informao enviada TV estar no intervalo, em eV, cuja ordem de grandeza vale (a) 101 (b) 102 (c) 103 (d) 104

(AFA - 2018) Um sistema gasoso constitudo por n mols de um gs perfeito passa do estado x para o estado y por meio dos processos distintos 1 e 2 mostrados no esquema a seguir. Se no processo 2 o sistema realiza um trabalho de 200 Je absorve uma quantidade de calor de 500 J correto afirmar que

(AFA - 2018) TEXTO PARA A PRXIMA QUESTO. FOOD SHORTAGE CAUSES, EFFECTS AND SOLUTIONS Food shortage is a serious problem facing the world and is prevalent in sub-Saharan Africa. The scarcity of food is caused by economic, environmental and social factors such as crop failure, overpopulation and poor government policies are the main cause of food scarcity in most countries. Environmental factors determine the kind of crops to be produced in a given place, economic factors determine the buying and production capacity and socio-political factors determine distribution of food to the masses. Food shortage has far reaching long and short term negative impacts which include starvation, malnutrition, increased mortality and political unrest1. There is need to collectively address the issue of food insecurity using both emergency and long term measures. Causes of food shortages There are a number of social factors causing food shortages. The rate of population increase is higher than increase in food production. The world is consuming more than it is producing, leading to decline in food stock and storage level and increased food prices due to soaring2 demand. Increased population has led to clearing of agricultural land for human settlement reducing agricultural production (Kamdor, 2007). Overcrowding of population in a given place results in urbanization of previously rich agricultural fields. Destruction of forests for human settlement, particularly tropical rain forest has led to climatic changes, such as prolonged droughts and desertification. Population increase means more pollution as people use more fuel in cars, industry, domestic cooking. The resultant effect is increased air and water pollution which affect the climate and food production. Environmental factors have greatly contributed to food shortage. Climatic change has reduced agricultural production. The change in climate is majorly caused by human activities and to some small extent natural activities. Increased combustion of fossil fuels due to increasing population through power plant, motor transport and mining of coal and oil emits green house gases which have continued to affect world climate. Deforestation of tropical forest due to human pressure has changed climatic patterns and rainfall seasons, and led to desertification which cannot support a crop production. Land degradation due to increased human activities has impacted negatively on agricultural production (Kamdor, 2007). Natural disasters such as floods, tropical storms and prolonged droughts are on the increase and have devastating impacts on food security particularly in developing countries. There are several economic factors that contribute to food shortage. Economic factors affect the ability of farmers to engage in agricultural production. Poverty situation in developing nations have reduced their capacity to produce food, as most farmers cannot afford seed and fertilizers. They use poor farming methods that cannot yield3 enough, even substantial use. Investments in agricultural research and developing are very low in developing nations. Recent global financial crisis have led to increase in food prices and reduced investments in agriculture by individuals and governments in developed nations resulting in reduced food production. Effects of food shortage There are a number of short term effects of food shortage. The impact on children, mothers and elderly are very evident as seen in malnutrition and hunger related deaths. Children succumb to hunger within short period as they cannot stand long period of starvation and they die even before the arrival of emergency assistance. There are also long term effects of food shortage. These include increase in the price of food as a result demand and supply forces. Increasing cost of food production due to the increase in fuel prices coupled with persistent drought in grain producing regions has contributed to the increase in the price of food in the world. Increase in oil price led to increase in the price of fertilizers, transportation of food and also industrial agriculture. Increasing food prices culminated in political instability and social unrest in several nations across the globe in 2007, in countries of Mexico, Cameroon, Brazil, Burkina Faso, Pakistan, Egypt and Bangladesh among other nations (Kamdor, 2007). Solution to problem of food shortage There are some solutions to the problem of food shortage. There is need to reduce production of carbon emissions and pollution to reduce the resultant climatic change through concerted and individual efforts. There is need to invest in clean energy such as solar, nuclear, and geothermal power in homes and industries, because they dont have adverse effects on the environment (Kamdor, 2007). Rich nations should help poor nations to develop and use clean and renewable energy in order to stabilize green house emissions into the atmosphere (Watson, nd). Government need to work in consultation with climatic bodies, World Bank and the UN to engage in projects aimed at promoting green environment. Conclusion Causes of food shortage are well known and can be solved if appropriate measures to solve the problem are taken and effectively implemented. Environmental causes of food shortages are changes in climatic and pollution due to human activities such overgrazing4 and deforestation which can be controlled through legislation. (Adapted from http://www.paypervids.com/food-shortage-causes- effects-solutions/Acesso em:14 fev 2017) Glossary: 1. unrest disagreement or fighting between different groups of people 2. soaring something that increases rapidly above the usual level 3. yield to supply or produce something such as profit or an amount or food 4. overgrazing excessive use of land where animals feed on grass Investing in clean energy is considered

(AFA - 2018) FOOD SHORTAGE CAUSES, EFFECTS AND SOLUTIONS Food shortage is a serious problem facing the world and is prevalent in sub-Saharan Africa. The scarcity of food is caused by economic, environmental and social factors such as crop failure, overpopulation and poor government policies are the main cause of food scarcity in most countries. Environmental factors determine the kind of crops to be produced in a given place, economic factors determine the buying and production capacity and socio-political factors determine distribution of food to the masses. Food shortage has far reaching long and short term negative impacts which include starvation, malnutrition, increased mortality and political unrest1. There is need to collectively address the issue of food insecurity using both emergency and long term measures. Causes of food shortages There are a number of social factors causing food shortages. The rate of population increase is higher than increase in food production. The world is consuming more than it is producing, leading to decline in food stock and storage level and increased food prices due to soaring2 demand. Increased population has led to clearing of agricultural land for human settlement reducing agricultural production (Kamdor, 2007). Overcrowding of population in a given place results in urbanization of previously rich agricultural fields. Destruction of forests for human settlement, particularly tropical rain forest has led to climatic changes, such as prolonged droughts and desertification. Population increase means more pollution as people use more fuel in cars, industry, domestic cooking. The resultant effect is increased air and water pollution which affect the climate and food production. Environmental factors have greatly contributed to food shortage. Climatic change has reduced agricultural production. The change in climate is majorly caused by human activities and to some small extent natural activities. Increased combustion of fossil fuels due to increasing population through power plant, motor transport and mining of coal and oil emits green house gases which have continued to affect world climate. Deforestation of tropical forest due to human pressure has changed climatic patterns and rainfall seasons, and led to desertification which cannot support a crop production. Land degradation due to increased human activities has impacted negatively on agricultural production (Kamdor, 2007). Natural disasters such as floods, tropical storms and prolonged droughts are on the increase and have devastating impacts on food security particularly in developing countries. There are several economic factors that contribute to food shortage. Economic factors affect the ability of farmers to engage in agricultural production. Poverty situation in developing nations have reduced their capacity to produce food, as most farmers cannot afford seed and fertilizers. They use poor farming methods that cannot yield3 enough, even substantial use. Investments in agricultural research and developing are very low in developing nations. Recent global financial crisis have led to increase in food prices and reduced investments in agriculture by individuals and governments in developed nations resulting in reduced food production. Effects of food shortage There are a number of short term effects of food shortage. The impact on children, mothers and elderly are very evident as seen in malnutrition and hunger related deaths. Children succumb to hunger within shortperiod as they cannot stand long period of starvation and they die even before the arrival of emergency assistance. There are also long term effects of food shortage. These include increase in the price of food as a result demand and supply forces. Increasing cost of food production due to the increase in fuel prices coupled with persistent drought in grain producing regions has contributed to the increase in the price of food in the world. Increase in oil price led to increase in the price of fertilizers, transportation of food and also industrial agriculture. Increasing food prices culminated in political instability and social unrest in several nations across the globe in 2007, in countries of Mexico, Cameroon, Brazil, Burkina Faso, Pakistan, Egypt and Bangladesh among other nations (Kamdor, 2007). Solution to problem of food shortage There are some solutions to the problem of food shortage. There is need to reduce production of carbon emissions and pollution to reduce the resultant climatic change through concerted and individual efforts. There is need to invest in clean energy such as solar, nuclear, and geothermal power in homes and industries, because they dont have adverse effects on the environment (Kamdor, 2007). Rich nations should help poor nations to develop and use clean and renewable energy in order to stabilize green house emissions into the atmosphere (Watson, nd). Government need to work in consultation with climatic bodies, World Bank and the UN to engage in projects aimed at promoting green environment. Conclusion Causes of food shortage are well known and can be solved if appropriate measures to solve the problem are taken and effectively implemented. Environmental causes of food shortages are changes in climatic and pollution due to human activities such overgrazing4 and deforestation which can be controlled through legislation. (Adapted from http://www.paypervids.com/food-shortage-causes- effects-solutions/Acesso em:14 fev 2017) Glossary: 1. unrest disagreement or fighting between different groups of people 2. soaring something that increases rapidly above the usual level 3. yield to supply or produce something such as profit or an amount or food 4. overgrazing excessive use of land where animals feed on grass Mark the option which best shows the meaning of the highlighted expression in deforestation of tropical forest due to human pressure (line 42)

(AFA - 2018) - Questo adaptada. FOOD SHORTAGE CAUSES, EFFECTS AND SOLUTIONS Food shortage is a serious problem facing the world and is prevalent in sub-Saharan Africa. The scarcity of food is caused by economic, environmental and social factors such as crop failure, overpopulation and poor government policies are the main cause of food scarcity in most countries. Environmental factors determine the kind of crops to be produced in a given place, economic factors determine the buying and production capacity and socio-political factors determine distribution of food to the masses. Food shortage has far reaching long and short term negative impacts which include starvation, malnutrition, increased mortality and political unrest. There is need to collectively address the issue of food insecurity using both emergency and long term measures. Causes of food shortages There are a number of social factors causing food shortages. The rate of population increase is higher than increase in food production. The world is consuming more than it is producing, leading to decline in food stock and storage level and increased food prices due to soaring demand. Increased population has led to clearing of agricultural land for human settlement reducing agricultural production (Kamdor, 2007). Overcrowding of population in a given place results in urbanization of previously rich agricultural fields. Destruction of forests for human settlement, particularly tropical rain forest has led to climatic changes, such as prolonged droughts and desertification. Population increase means more pollution as people use more fuel in cars, industry, domestic cooking. The resultant effect is increased air and water pollution which affect the climate and food production. Environmental factors have greatly contributed to food shortage. Climatic change has reduced agricultural production. The change in climate is majorly caused by human activities and to some small extent natural activities. Increased combustion of fossil fuels due to increasing population through power plant, motor transport and mining of coal and oil emits green house gases which have continued to affect world climate. Deforestation of tropical forest due to human pressure has changed climatic patterns and rainfall seasons, and led to desertification which cannot support a crop production. Land degradation due to increased human activities has impacted negatively on agricultural production (Kamdor, 2007). Natural disasters such as floods, tropical storms and prolonged droughts are on the increase and have devastating impacts on food security particularly in developing countries. There are several economic factors that contribute to food shortage. Economic factors affect the ability of farmers to engage in agricultural production. Poverty situation in developing nations have reduced their capacity to produce food, as most farmers cannot afford seed and fertilizers. They use poor farming methods that cannot yield enough, even substantial use. Investments in agricultural research and developing are very low in developing nations. Recent global financial crisis have led to increase in food prices and reduced investments in agriculture by individuals and governments in developed nations resulting in reduced food production. Effects of food shortage There are a number of short term effects of food shortage. The impact on children, mothers and elderly are very evident as seen in malnutrition and hunger related deaths. Children succumb to hunger within short period as they cannot stand long period of starvation and they die even before the arrival of emergency assistance. There are also long term effects of food shortage. These include increase in the price of food as a result demand and supply forces. Increasing cost of food production due to the increase in fuel prices coupled with persistent drought in grain producing regions has contributed to the increase in the price of food in the world. Increase in oil price led to increase in the price of fertilizers, transportation of food and also industrial agriculture. Increasing food prices culminated in political instability and social unrest in several nations across the globe in 2007, in countries of Mexico, Cameroon, Brazil, Burkina Faso, Pakistan, Egypt and Bangladesh among other nations (Kamdor, 2007). Solution to problem of food shortage There are some solutions to the problem of food shortage. There is need to reduce production of carbon emissions and pollution to reduce the resultant climatic change through concerted and individual efforts. There is need to invest in clean energy such as solar, nuclear, and geothermal power in homes and industries, because they dont have adverse effects on the environment (Kamdor, 2007). Rich nations should help poor nations to develop and use clean and renewable energy in order to stabilize green house emissions into the atmosphere (Watson, nd). Government need to work in consultation with climatic bodies, World Bank and the UN to engage in projects aimed at promoting green environment. Conclusion Causes of food shortage are well known and can be solved if appropriate measures to solve the problem are taken and effectively implemented. Environmental causes of food shortages are changes in climatic and pollution due to human activities such overgrazing and deforestation which can be controlled through legislation. (Adapted from http://www.paypervids.com/food-shortage-causes- effects-solutions/Acesso em:14 fev 2017) Glossary: 1. unrest disagreement or fighting between different groups of people 2. soaring something that increases rapidly above the usual level 3. yield to supply or produce something such as profit or an amount or food The personal pronoun they underlined refers to

(AFA - 2018) Quando necessrio use: - Acelereao da gravidade: g = 10 m/s2; - sen 19 = cos 71 = 0,3; - sen 71 = cos 19 = 0,9; - Velocidade da luz no vcuo: c = 3,0108m/s; - Constante de Planck: h = 6,610-34Js; - 1 eV = 1,610-19J; Um recipiente vazio, perfeitamente transparente, no formato de uma lente esfrica delgada gaussiana, de raio a, preenchido com gua lmpida e cristalina at a metade de sua capacidade (Figura 1). Essa lente ento fixada a uma determinada distncia de uma fotografia quadrada de lado 3a (Figura 2), tendo seus centros geomtricos alinhados (Figura 3). Considerando que o sistema lente-fotografia esteja imerso no ar, um observador na posio O (Figura 3), poder observar, dentre as opes abaixo, a imagem da situao apresentada, como sendo

(AFA - 2018) QUESTO ANULADA NA PROVA OFICIAL Trs cargas eltricas pontuais, q1, q2e q3esto fixas de tal forma que os segmentos de reta que unem cada par de carga formam um tringulo equiltero com o plano na vertical, conforme ilustra a figura a seguir. M o ponto mdio do segmento que une q2e q3.A carga eltrica q2 positiva e igual a Qenquanto que q1e q3 so desconhecidas.Verifica-se que o vetor campo eltrico Eno ponto Mgerado por estas trs cargas, forma com o lado que une q2e q3um ngulo de 19e est apontado para baixo. Sabendo-se, ainda, que a fora eltrica de interao entre as cargas q1e q2 menor que a fora eltrica entre q2e q3, correto afirmar que:

(AFA - 2018) FOOD SHORTAGE CAUSES, EFFECTS AND SOLUTIONS Food shortage is a serious problem facing the world and is prevalent in sub-Saharan Africa. The scarcity of food is caused by economic, environmental and social factors such as crop failure, overpopulation and poor government policies are the main cause of food scarcity in most countries. Environmental factors determine the kind of crops to be produced in a given place, economic factors determine the buying and production capacity and socio-political factors determine distribution of food to the masses. Food shortage has far reaching long and short term negative impacts which include starvation, malnutrition, increased mortality and political unrest. There is need to collectively address the issue of food insecurity using both emergency and long term measures. Causes of food shortages There are a number of social factors causing food shortages. The rate of population increase is higher than increase in food production. The world is consuming more than it is producing, leading to decline in food stock and storage level and increased food prices due to soaring demand. Increased population has led to clearing of agricultural land for human settlement reducing agricultural production (Kamdor, 2007). Overcrowding of population in a given place results in urbanization of previously rich agricultural fields. Destruction of forests for human settlement, particularly tropical rain forest has led to climatic changes, such as prolonged droughts and desertification. Population increase means more pollution as people use more fuel in cars, industry, domestic cooking. The resultant effect is increased air and water pollution which affect the climate and food production. Environmental factors have greatly contributed to food shortage. Climatic change has reduced agricultural production. The change in climate is majorly caused by human activities and to some small extent natural activities. Increased combustion of fossil fuels due to increasing population through power plant, motor transport and mining of coal and oil emits green house gases which have continued to affect world climate. Deforestation of tropical forest due to human pressure has changed climatic patterns and rainfall seasons, and led to desertification which cannot support a crop production. Land degradation due to increased human activities has impacted negatively on agricultural production (Kamdor, 2007). Natural disasters such as floods, tropical storms and prolonged droughts are on the increase and have devastating impacts on food security particularly in developing countries. There are several economic factors that contribute to food shortage. Economic factors affect the ability of farmers to engage in agricultural production. Poverty situation in developing nations have reduced their capacity to produce food, as most farmers cannot afford seed and fertilizers. They use poor farming methods that cannot yield enough, even substantial use. Investments in agricultural research and developing are very low in developing nations. Recent global financial crisis have led to increase in food prices and reduced investments in agriculture by individuals and governments in developed nations resulting in reduced food production. Effects of food shortage There are a number of short term effects of food shortage. The impact on children, mothers and elderly are very evident as seen in malnutrition and hunger related deaths. Children succumb to hunger within short period as they cannot stand long period of starvation and they die even before the arrival of emergency assistance. There are also long term effects of food shortage. These include increase in the price of food as a result demand and supply forces. Increasing cost of food production due to the increase in fuel prices coupled with persistent drought in grain producing regions has contributed to the increase in the price of food in the world. Increase in oil price led to increase in the price of fertilizers, transportation of food and also industrial agriculture. Increasing food prices culminated in political instability and social unrest in several nations across the globe in 2007, in countries of Mexico, Cameroon, Brazil, Burkina Faso, Pakistan, Egypt and Bangladesh among other nations (Kamdor, 2007). Solution to problem of food shortage There are some solutions to the problem of food shortage. There is need to reduce production of carbon emissions and pollution to reduce the resultant climatic change through concerted and individual efforts. There is need to invest in clean energy such as solar, nuclear, and geothermal power in homes and industries, because they dont have adverse effects on the environment (Kamdor, 2007). Rich nations should help poor nations to develop and use clean and renewable energy in order to stabilize green house emissions into the atmosphere (Watson, nd). Government need to work in consultation with climatic bodies, World Bank and the UN to engage in projects aimed at promoting green environment. Conclusion Causes of food shortage are well known and can be solved if appropriate measures to solve the problem are taken and effectively implemented. Environmental causes of food shortages are changes in climatic and pollution due to human activities such overgrazing and deforestation which can be controlled through legislation. (Adapted from http://www.paypervids.com/food-shortage-causes- effects-solutions/Acesso em:14 fev 2017) Glossary: 1. unrest disagreement or fighting between different groups of people 2. soaring something that increases rapidly above the usual level 3. yield to supply or produce something such as profit or an amount or food In poverty situation in developing nations have reduced their capacity to produce food, as most farmers cannot afford seed and fertilizers (lines 53 to 55), the underlined word means

(AFA - 2018) TEXTO PARA A PRXIMA QUESTO. FOOD SHORTAGE CAUSES, EFFECTS AND SOLUTIONS Food shortage is a serious problem facing the world and is prevalent in sub-Saharan Africa. The scarcity of food is caused by economic, environmental and social factors such as crop failure, overpopulation and poor government policies are the main cause of food scarcity in most countries. Environmental factors determine the kind of crops to be produced in a given place, economic factors determine the buying and production capacity and socio-political factors determine distribution of food to the masses. Food shortage has far reaching long and short term negative impacts which include starvation, malnutrition, increased mortality and political unrest1. There is need to collectively address the issue of food insecurity using both emergency and long term measures. Causes of food shortages There are a number of social factors causing food shortages. The rate of population increase is higher than increase in food production. The world is consuming more than it is producing, leading to decline in food stock and storage level and increased food prices due to soaring2 demand. Increased population has led to clearing of agricultural land for human settlement reducing agricultural production (Kamdor, 2007). Overcrowding of population in a given place results in urbanization of previously rich agricultural fields. Destruction of forests for human settlement, particularly tropical rain forest has led to climatic changes, such as prolonged droughts and desertification. Population increase means more pollution as people use more fuel in cars, industry, domestic cooking. The resultant effect is increased air and water pollution which affect the climate and food production. Environmental factors have greatly contributed to food shortage. Climatic change has reduced agricultural production. The change in climate is majorly caused by human activities and to some small extent natural activities. Increased combustion of fossil fuels due to increasing population through power plant, motor transport and mining of coal and oil emits green house gases which have continued to affect world climate. Deforestation of tropical forest due to human pressure has changed climatic patterns and rainfall seasons, and led to desertification which cannot support a crop production. Land degradation due to increased human activities has impacted negatively on agricultural production (Kamdor, 2007). Natural disasters such as floods, tropical storms and prolonged droughts are on the increase and have devastating impacts on food security particularly in developing countries. There are several economic factors that contribute to food shortage. Economic factors affect the ability of farmers to engage in agricultural production. Poverty situation in developing nations have reduced their capacity to produce food, as most farmers cannot afford seed and fertilizers. They use poor farming methods that cannot yield3 enough, even substantial use. Investments in agricultural research and developing are very low in developing nations. Recent global financial crisis have led to increase in food prices and reduced investments in agriculture by individuals and governments in developed nations resulting in reduced food production. Effects of food shortage There are a number of short term effects of food shortage. The impact on children, mothers and elderly are very evident as seen in malnutrition and hunger related deaths. Children succumb to hunger within short period as they cannot stand long period of starvation and they die even before the arrival of emergency assistance. There are also long term effects of food shortage. These include increase in the price of food as a result demand and supply forces. Increasing cost of food production due to the increase in fuel prices coupled with persistent drought in grain producing regions has contributed to the increase in the price of food in the world. Increase in oil price led to increase in the price of fertilizers, transportation of food and also industrial agriculture. Increasing food prices culminated in political instability and social unrest in several nations across the globe in 2007, in countries of Mexico, Cameroon, Brazil, Burkina Faso, Pakistan, Egypt and Bangladesh among other nations (Kamdor, 2007). Solution to problem of food shortage There are some solutions to the problem of food shortage. There is need to reduce production of carbon emissions and pollution to reduce the resultant climatic change through concerted and individual efforts. There is need to invest in clean energy such as solar, nuclear, and geothermal power in homes and industries, because they dont have adverse effects on the environment (Kamdor, 2007). Rich nations should help poor nations to develop and use clean and renewable energy in order to stabilize green house emissions into the atmosphere (Watson, nd). Government need to work in consultation with climatic bodies, World Bank and the UN to engage in projects aimed at promoting green environment. Conclusion Causes of food shortage are well known and can be solved if appropriate measures to solve the problem are taken and effectively implemented. Environmental causes of food shortages are changes in climatic and pollution due to human activities such overgrazing4 and deforestation which can be controlled through legislation. (Adapted from http://www.paypervids.com/food-shortage-causes- effects-solutions/Acesso em:14 fev 2017) Glossary: 1. unrest disagreement or fighting between different groups of people 2. soaring something that increases rapidly above the usual level 3. yield to supply or produce something such as profit or an amount or food 4. overgrazing excessive use of land where animals feed on grass The scarcity of food may lead to long term effects such as

(AFA - 2018) Em muitos problemas de fsica desprezam-se as foras de resistncia ao movimento. Entretanto, sabe-se que, na prtica, essas foras so significativas e muitas vezes desempenham um papel determinante. Por exemplo, no automobilismo, os veculos comumente possuem dispositivos aerodinmicos implementados, os quais tm a funo de contribuir para o aumento da Downforce, uma fora vertical, inversa sustentao, que busca incrementar a aderncia dos pneus ao asfalto atravs de um acrscimo na carga normal, permitindo que o veculo possa realizar as curvas com uma velocidade maior do que o faria sem estes dispositivos. (Trecho retirado da monografia intitulada Sistema ativo de reduo de arrasto aerodinmico por atuador aplicado a um prottipo de frmula SAE, de autoria de Danilo Barbosa Porto, apresentada na Escola de Engenharia de So Carlos, da Universidade de So Paulo, em 2016). Para avaliar o papel da Downforce, considere um carro de Frmula 1, de massa M, realizando uma curva em determinada pista plana. Ao se desprezar completamente os efeitos produzidos pelo seu movimento em relao ao ar, mas considerando o atrito entre pneus e o asfalto, o carro consegue fazer a curva, sem derrapar, a uma velocidade mxima V. Porm, ao levar em conta, especificamente, a atuao da Downforce D (desconsiderando a fora de arrasto) a velocidade mxima V do carro, nessa mesma curva, muda em funo de D. Nessas condies, o grfico que melhor representa a relao em funo de D

(AFA - 2018) TEXTO PARA A PRXIMA QUESTO. FOOD SHORTAGE CAUSES, EFFECTS AND SOLUTIONS Food shortage is a serious problem facing the world and is prevalent in sub-Saharan Africa. The scarcity of food is caused by economic, environmental and social factors such as crop failure, overpopulation and poor government policies are the main cause of food scarcity in most countries. Environmental factors determine the kind of crops to be produced in a given place, economic factors determine the buying and production capacity and socio-political factors determine distribution of food to the masses. Food shortage has far reaching long and short term negative impacts which include starvation, malnutrition, increased mortality and political unrest1. There is need to collectively address the issue of food insecurity using both emergency and long term measures. Causes of food shortages There are a number of social factors causing food shortages. The rate of population increase is higher than increase in food production. The world is consuming more than it is producing, leading to decline in food stock and storage level and increased food prices due to soaring2 demand. Increased population has led to clearing of agricultural land for human settlement reducing agricultural production (Kamdor, 2007). Overcrowding of population in a given place results in urbanization of previously rich agricultural fields. Destruction of forests for human settlement, particularly tropical rain forest has led to climatic changes, such as prolonged droughts and desertification. Population increase means more pollution as people use more fuel in cars, industry, domestic cooking. The resultant effect is increased air and water pollution which affect the climate and food production. Environmental factors have greatly contributed to food shortage. Climatic change has reduced agricultural production. The change in climate is majorly caused by human activities and to some small extent natural activities. Increased combustion of fossil fuels due to increasing population through power plant, motor transport and mining of coal and oil emits green house gases which have continued to affect world climate. Deforestation of tropical forest due to human pressure has changed climatic patterns and rainfall seasons, and led to desertification which cannot support a crop production. Land degradation due to increased human activities has impacted negatively on agricultural production (Kamdor, 2007). Natural disasters such as floods, tropical storms and prolonged droughts are on the increase and have devastating impacts on food security particularly in developing countries. There are several economic factors that contribute to food shortage. Economic factors affect the ability of farmers to engage in agricultural production. Poverty situation in developing nations have reduced their capacity to produce food, as most farmers cannot afford seed and fertilizers. They use poor farming methods that cannot yield3 enough, even substantial use. Investments in agricultural research and developing are very low in developing nations. Recent global financial crisis have led to increase in food prices and reduced investments in agriculture by individuals and governments in developed nations resulting in reduced food production. Effects of food shortage There are a number of short term effects of food shortage. The impact on children, mothers and elderly are very evident as seen in malnutrition and hunger related deaths. Children succumb to hunger within short period as they cannot stand long period of starvation and they die even before the arrival of emergency assistance. There are also long term effects of food shortage. These include increase in the price of food as a result demand and supply forces. Increasing cost of food production due to the increase in fuel prices coupled with persistent drought in grain producing regions has contributed to the increase in the price of food in the world. Increase in oil price led to increase in the price of fertilizers, transportation of food and also industrial agriculture. Increasing food prices culminated in political instability and social unrest in several nations across the globe in 2007, in countries of Mexico, Cameroon, Brazil, Burkina Faso, Pakistan, Egypt and Bangladesh among other nations (Kamdor, 2007). Solution to problem of food shortage There are some solutions to the problem of food shortage. There is need to reduce production of carbon emissions and pollution to reduce the resultant climatic change through concerted and individual efforts. There is need to invest in clean energy such as solar, nuclear, and geothermal power in homes and industries, because they dont have adverse effects on the environment (Kamdor, 2007). Rich nations should help poor nations to develop and use clean and renewable energy in order to stabilize green house emissions into the atmosphere (Watson, nd). Government need to work in consultation with climatic bodies, World Bank and the UN to engage in projects aimed at promoting green environment. Conclusion Causes of food shortage are well known and can be solved if appropriate measures to solve the problem are taken and effectively implemented. Environmental causes of food shortages are changes in climatic and pollution due to human activities such overgrazing4 and deforestation which can be controlled through legislation. (Adapted from http://www.paypervids.com/food-shortage-causes- effects-solutions/Acesso em:14 fev 2017) Glossary: 1. unrest disagreement or fighting between different groups of people 2. soaring something that increases rapidly above the usual level 3. yield to supply or produce something such as profit or an amount or food 4. overgrazing excessive use of land where animals feed on grass Starvation, malnutrition, increased mortality and political unrest are mentioned in the text as examples of

(AFA - 2018) TEXTO PARA A PRXIMA QUESTO. FOOD SHORTAGE CAUSES, EFFECTS AND SOLUTIONS Food shortage is a serious problem facing the world and is prevalent in sub-Saharan Africa. The scarcity of food is caused by economic, environmental and social factors such as crop failure, overpopulation and poor government policies are the main cause of food scarcity in most countries. Environmental factors determine the kind of crops to be produced in a given place, economic factors determine the buying and production capacity and socio-political factors determine distribution of food to the masses. Food shortage has far reaching long and short term negative impacts which include starvation, malnutrition, increased mortality and political unrest1. There is need to collectively address the issue of food insecurity using both emergency and long term measures. Causes of food shortages There are a number of social factors causing food shortages. The rate of population increase is higher than increase in food production. The world is consuming more than it is producing, leading to decline in food stock and storage level and increased food prices due to soaring2 demand. Increased population has led to clearing of agricultural land for human settlement reducing agricultural production (Kamdor, 2007). Overcrowding of population in a given place results in urbanization of previously rich agricultural fields. Destruction of forests for human settlement, particularly tropical rain forest has led to climatic changes, such as prolonged droughts and desertification. Population increase means more pollution as people use more fuel in cars, industry, domestic cooking. The resultant effect is increased air and water pollution which affect the climate and food production. Environmental factors have greatly contributed to food shortage. Climatic change has reduced agricultural production. The change in climate is majorly caused by human activities and to some small extent natural activities. Increased combustion of fossil fuels due to increasing population through power plant, motor transport and mining of coal and oil emits green house gases which have continued to affect world climate. Deforestation of tropical forest due to human pressure has changed climatic patterns and rainfall seasons, and led to desertification which cannot support a crop production. Land degradation due to increased human activities has impacted negatively on agricultural production (Kamdor, 2007). Natural disasters such as floods, tropical storms and prolonged droughts are on the increase and have devastating impacts on food security particularly in developing countries. There are several economic factors that contribute to food shortage. Economic factors affect the ability of farmers to engage in agricultural production. Poverty situation in developing nations have reduced their capacity to produce food, as most farmers cannot afford seed and fertilizers. They use poor farming methods that cannot yield3 enough, even substantial use. Investments in agricultural research and developing are very low in developing nations. Recent global financial crisis have led to increase in food prices and reduced investments in agriculture by individuals and governments in developed nations resulting in reduced food production. Effects of food shortage There are a number of short term effects of food shortage. The impact on children, mothers and elderly are very evident as seen in malnutrition and hunger related deaths. Children succumb to hunger within short period as they cannot stand long period of starvation and they die even before the arrival of emergency assistance. There are also long term effects of food shortage. These include increase in the price of food as a result demand and supply forces. Increasing cost of food production due to the increase in fuel prices coupled with persistent drought in grain producing regions has contributed to the increase in the price of food in the world. Increase in oil price led to increase in the price of fertilizers, transportation of food and also industrial agriculture. Increasing food prices culminated in political instability and social unrest in several nations across the globe in 2007, in countries of Mexico, Cameroon, Brazil, Burkina Faso, Pakistan, Egypt and Bangladesh among other nations (Kamdor, 2007). Solution to problem of food shortage There are some solutions to the problem of food shortage. There is need to reduce production of carbon emissions and pollution to reduce the resultant climatic change through concerted and individual efforts. There is need to invest in clean energy such as solar, nuclear, and geothermal power in homes and industries, because they dont have adverse effects on the environment (Kamdor, 2007). Rich nations should help poor nations to develop and use clean and renewable energy in order to stabilize green house emissions into the atmosphere (Watson, nd). Government need to work in consultation with climatic bodies, World Bank and the UN to engage in projects aimed at promoting green environment. Conclusion Causes of food shortage are well known and can be solved if appropriate measures to solve the problem are taken and effectively implemented. Environmental causes of food shortages are changes in climatic and pollution due to human activities such overgrazing4 and deforestation which can be controlled through legislation. (Adapted from http://www.paypervids.com/food-shortage-causes- effects-solutions/Acesso em:14 fev 2017) Glossary: 1. unrest disagreement or fighting between different groups of people 2. soaring something that increases rapidly above the usual level 3. yield to supply or produce something such as profit or an amount or food 4. overgrazing excessive use of land where animals feed on grass Overcrowding of population (line 25) in the text means a

(AFA - 2018) Quando necessrio, use: Acelerao da gravidade: g = 10 m/s2; sen 19 = cos 71 = 0,3; sen 71 = cos 19 = 0,9; Velocidade da luz no vcuo: c = 3,0 108m/s; Constante de Planck: h = 6,6 10-34J s; 1 eV = 1,6 1019J; Potencial eltrico no infinito: zero. Dois recipientes A e B, contendo o mesmo volume de gua, so colocados separadamente sobre duas balanas I e II, respectivamente, conforme indicado na figura a seguir. A nica diferena entre os recipientes A e B est no fato de que B possui um ladro que permite que a gua escoe para um outro recipiente C, localizado fora das balanas. Em seguida, mergulha-se, lentamente, sem girar e com velocidade constante, por meio de um fio ideal, em cada recipiente, um cilindro metlico, macio, de material no homogneo, de tal forma que o seu eixo sempre se mantm na vertical. Os cilindros vo imergindo na gua, sem provocar variao de temperatura e sem encostar nas paredes e nos fundos dos recipientes, de tal forma que os lquidos, nos recipientes A e B, sempre estaro em equilbrio hidrosttico no momento da leitura nas balanas. O grfico que melhor representa a leitura L das balanas I e II, respectivamente, LI e LII, em funo da altura h submersa de cada cilindro