One of the main tasks of engine manufacturers is to increase the KDP, which ideally should reach 100%. But at the moment, the internal combustion engines used in cars are far from ideal. During their operation, a significant part of the energy is spent on friction and heating. Due to the resulting heating, cooling systems have to be installed in the car. At the moment, the most common liquid cooling system of a car engine. A cooling liquid (antifreeze or antifreeze) is poured into it, which circulates through the system under pressure, cooling the corresponding units. Within the framework of this article, we will consider exactly what kind of pressure is created in the cooling system, how it happens, as well as other issues related to the topic.
m = 5 л
Δt = 20°C
НАЙТИ:
Q - ?
РЕШЕНИЕ:
1) Q = cmΔt - формула расчета количества теплоты;
c - это удельная теплоемкость
(существует таблица удельной теплоемкости для разных веществ; мы и заглянем в таблицу).
Eдельная теплоемкость растительного масла (подсолнечного) равна:
c = 1700 Дж/кг · °C
(Джоуль, деленный на кг, умноженный на градус цельсия)
Подставляем в формулу. Получаем:
2) Q = cmΔt →
Q = 1700·5·20 = 170 000 Дж - потребуется.
ответ: 170 000 Дж