В кастрюлю кипящей воды объемом 2л поместили слиток серебра массой 100г. Найдите количество теплоты, полученное слитком серебра, если
известно, что после погружения слиток нагрелась до 80°С. Считать, что в
конце процесса теплообмена температура воды равна температуре слитка.
Объяснение:
Newspapers and magazines play a very important part in our life. Practically there is no family that does not read them. We can learn many things from newspapers. Perhaps that is why many years ago an American humorous writer said: "All I know is what I see in the papers"; and another American author more than half a century ago wrote that "the careful reader of a few good newspapers can learn more in a year than most scientists do in their great libraries".
We can agree or disagree with these statements (better to disagree, because scientific books and magazines have more information than newspapers), but we'll have to say that newspapers help us in many ways. There are a lot of different kinds of newspapers in our country. One can buy them practically everywhere. It is impossible to read all the newspapers and magazines. Everyone has favourite ones.
My favourite newspaper is "Komsomolskaya Pravda". We can read almost about everything in this newspaper. There are articles dealing with home and abroad news, sport events, life of favourite actors and singers and even the weather. We can find many interesting things there. We can read some useful pieces of advice, some stories about our life, and so on. There are puzzles, songs and even anecdotes there. "Komsomolskaya Pravda" is one of the most interesting newspapers, to my mind.
ответ: в воду опустили кирпич Cб = 879 Дж/кг *°C.
Объяснение:
mб = 500 г = 0,5 кг.
tб 18 °C.
mв = 400 г = 0,4 кг.
Cв = 4200 Дж/кг *°C.
tв = 100 °C.
t = 83 °C.
Cб - ?
Для определения вещества из которого сделан брусок, необходимо определить удельную теплоёмкость материала из которого сделан брусок Cб.
Qб = Qв.
Qб = Cб *mб *(t - tб).
Qв = Cв *mв *(tв - t).
Cб *mб *(t - tб) = Cв *mв *(tв - t).
Cб = Cв *mв *(tв - t) /mб *(t - tб).
Cб = 4200 Дж/кг *°C *0,4 кг *(100 °C - 83 °C) /0,5 кг *(83 °C - 18 °C) = 879 Дж/кг *°C.
Согласно таблицы удельной теплоёмкости веществ, Cб = 879 Дж/кг *°C соответствует материал кирпич.
ответ: в воду опустили кирпич Cб = 879 Дж/кг *°C.