Что быстрее радиоволны или ультрафиолетовой луч

Объяснение:

Определить КПД атомной электростанции, мощность которой 6 МВт, если в течение суток в реакторе используется 35 г Урана-235?

При делении одного ядра урана выделяется энергия 200 МэВ.

(1 эВ = 1,6·10⁻¹⁹ Дж).

Дано:

N = 6 МВт = 6·10⁶ Вт

t = 1 сутки = 86 400 c

m = 37 г

M = 235 г/моль - молярная масса урана-235

q₁ = 200 МэВ = 200·10⁶ эВ

e = 1,6·10⁻¹⁹ Кл

Nₐ = 6,02·10²³  моль⁻¹

КПД - ?

1)

Найдем количество радиоактивного вещества:

ν = m / M = 35 / 235 ≈ 0,15 моль

2)

Находим число распавшихся атомов:

N = ν·Nₐ = 0,15·6,02·10²³ ≈ 9·10²²

3)

Находим выделившуюся энергию:

Q = N·q₁·e = 9·10²²·200·10⁶·1,6·10⁻¹⁹ ≈ 2,9·10¹² Дж    (1)

4)

Полезная энергия:

Q₁ = N·t = 6·10⁶·86 400 ≈ 0,5·10¹² Дж  (2)

5)

КПД = Q₁·100% / Q = 0,5·10¹² · 100% / (2,9·10¹²) =

= 50 / 2,9 ≈ 17 %

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