A partir de um fóton y, ocorre a formação de pares, resultando em um elétron e um pósitron. A energia do fóton era de 2,62 MeV. A energia cinética do par formado, em MeV, é

Dados:

• massa de repouso do elétron: 9,11 x10⁻³¹ kg

• velocidade da luz no vácuo: 3,00 x 10⁸ m/s

• 1 MeV = 1,63 x 10⁻¹³ J

Em um gás ideal, a energia interna é considerada uma variável de estado e é função que depende basicamente de

Butler believes that the American Congress and Obama Administration must support the use of nuclear power by

According to Butler, the dangers usually associated with nuclear energy have generated

The word in parentheses describes the idea expressed by the term in boldtype in

In the fragments “…excessive legal and permitting delays are pushing up the capital cost of new nuclear-power plants …” (lines 14-16) and “…we´ll throw out to be buried in landfills.” (lines 39-40), the phrases “pushing up” and “throw out”, are replaced, without substantial change in meaning, by

Based on the meanings of the words in the text, it can be said that