Предмет: Физика, автор: руслан2324342

При обработке алюминиевой детали на станке температура ее повысилась от 20 до 420 °С. На сколько при этом изменилась внутренняя энергия детали, если ее масса 500 г?

Какое количество теплоты выделится при охлаждении на 80 °С свинцовой детали массой 400 г?

Какое количество теплоты выделится при полном сгорании 20 г водорода?

II

На сколько градусов охладится 40 г льда, если он при этом отдает количество теплоты 500 Дж?

Алюминиевая кастрюля массой 250 г вмещает 2 кг молока. Какое количество теплоты требуется для нагревания в этой кастрюле молока от 15 до 100 °С?

Рассчитайте массу керосина, который потребуется сжечь для того, чтобы нагреть 10 кг воды от 10 до 80 °С, если считать, что вся энергия, выделенная при сгорании керосина, пойдет на нагрев воды.

III

Определите, какая часть энергии (в %) расходуется на нагревание воды спиртовкой, если для нагревания 100 г воды от 20 до 90 °С сожгли 5 г спирта.

Для ванны необходимо приготовить воду с температурой 36 °С. Из горячего крана смесителя идет вода при температуре 80 °С, а из холодного — при 8 °С. Сколько надо взять горячей воды, чтобы приготовить ванну, если для этого потребуется 196 кг холодной воды?

Как изменится температура воды массой 880 г, если ей сообщить такое же количество теплоты, какое идет на нагревание алюминиевого цилиндра массой 2 кг на 200 °С?

Ответы

Автор ответа: ColdMand

Дано:
m= 0,5 кг
t1=20°
t2=420°
c=920

Решение:
Q=cm(t2-t1)
Q=920*0,5*400=184000 Дж=184 кДж

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