Pré Marista

EXERCÍCIOS DE REVISÃO - CIRCUITOS ELÉTRICOS

Prof.: Johnson Rodrigues

1.1)Dois resistores, um de 400Ω e outro de 600Ω, ligados em série, estão submetidos à tensão de

de 200V.

a)a)Qual é a corrente que percorre esses resistores?

b)b)Qual é a tensão aplicada no resistor de 600Ω?

2.2)Um circuito em paralelo de resistores é percorrido por uma corrente de 1 A . Sabendo-se que

R1= 12Ω e a tensão entre os terminais do circuito é 3V, determine:

a)a)A corrente elétrica que passa por R1= 12Ω;

b)b)O valor de R2 .

3.3)A uma bateria de 12 V ligam-se dois resistores pelos quais passam, respectivamente, 0,5 A e 1,5 A.

a)a)Qual a carga fornecida pela bateria durante 5 min ?

b)b)Qual a potência total dissipada nos resistores?

c)c)Qual a resistência equivalente do circuito?

A Brazilian Timeline.

Thinking forward to the Brazil 2014 World cup it is hard to think of a time when there was no FIFA World Cup. The tournament which graces us with its presence every 4 years is probably only second on a global stage to the Olympic Games due to the number of nations who attend each four year celeb2ration of sporting excellence. Yet before 1930 (when Brazil lost 2-1 to Yugoslavia), there was no world cup. There was no competition to determine the best international side in the world.

Thanks, however, to FIFA President Jules Rimetinternational football would be changed forever. It was proposed that the first world cup would take place in Uruguay as a result of them being Olympic champions. It was the only World Cup where qualifying wouldn’t take place and invitations were sent out to all major footballing nations. The response to the idea of a global tournament was not a warm one. A number of nations decided against entering the tournament, England most notably, citing a number of reasons for their non attendance. So, despite the low attendance, only 13 teams contested, when the tournament kicked off, Jules Rimet was able to realize his dream to determine who would become the first ever world champions.

Ultimately, it was the host nation who triumphed and went on to raise the Jules Rimet trophy, but from such inauspicious and humble beginnings the World Cup has gone from strength to strength and is now contested by thirty two international teams in attendance from all corners of the globe. It is an event watched by billions and something that every football fan positively salivates over and dreams of watching their side stand alone as the Champions of the World. This timeline follows the history and successes of one of the sides who has competed in every single World Cup since its inception, Brazil.

Since the format began, Brazil have been the major success story of the tournament with a record five victories, enthralling and entertaining sides with their brand of fantasy football. Their sides have fielded some of the greatest names in footballing history, produced arguably the greatest team of all time in Mexico 1970 and given football fans one of the two finest players ever to grace the football stage. They are a major reason behind the competition’s massive popularity and will, no doubt, lavish us with a wonderful tournament in six years time. That is the in future, so let us look at the past and go back in time to Uruguay in 1930 and see how it all began for the boys from Brazil.

Women take reins of power in Latin America, but not in U.S.

By TeoBallve, January 13, 2011

The inauguration of Brazil’s first female president is a stark reminder that the United States lags far behind its Latin American neighbors in electing women to power.

DilmaRousseff took Brazil’s presidential oath on Jan. 1, becoming the leader of Latin America’s largest and most powerful country.

Long stereotyped for its particular brand of male chauvinism or “machismo” — a scourge that undeniably remains — Latin America is now leading the way toward greater gender parity in positions of power.

Since 1990, Argentina, Chile, Costa Rica, Guyana, Nicaragua and Panama have all elected women presidents. And Peru might follow suit in its April elections.

Rousseff’s victory in Brazil is in many ways a culmination of what some call Latin America’s “Pink Tide.”

Rousseff emerged from humble origins, the daughter of a schoolteacher and a Bulgarian immigrant, rising through the ranks of Brazil’s grassroots Workers’ Party. She cut her political teeth fighting against Brazil’s brutal military dictatorship in the 1960s. For her efforts, she was thrown in jail, where she was repeatedly beaten and tortured with electric shocks during nearly three years of imprisonment.

In the 1970s, Chile’s future President Michelle Bachelet(2006-2010) endured similar traumas under military rule in her own country.

In those years, obsessed with an exaggerated communist threat, Washington gave strong backing to South America’s most authoritarian governments. The military regimes sought to wipe out the progressive political movements that produced women like Rousseff, Bachelet, and current Argentine President

Cristina Kirchner.

As presidents, these women have helped end the days when Latin American governments took their orders from Washington. They are also consolidating the region’s hard-won democratic gains — in part, by assuring that more women are in positions of power.

At her inauguration, Rousseff made reference to the historic ascendance of women in Brazil.

“I am not here to boast of my own life story, but rather to praise the life of every Brazilian woman,” Rousseff said. “I am here to open doors so that in the future many other women can also be president.”

We in the United States have a lot to learn from the rise of women in Latin America. We still have never had a woman president. And only 17 percent of members of Congress are women, which is less than many countries in Latin America. Twelve Latin American and Caribbean nations actually have gender quotas for their legislators. These quotas run as high as 50 percent in Bolivia and 40 percent in Argentina, Costa Rica and Mexico.

In the United States, we need to look more closely at our own gender disparities, and we need to identify them for what they are: a serious social and political problem.

TeoBallve is a journalist and editor specializing in Latin American affairs. He can be reached at pmproj@progressive.org