Question

Какое количество теплоты выделится при охлаждении стальной болванки массой 200 килограмм от 800 градусов до 15 градусов по Цельсию

Answer 1

Дано:
m = 200кг
t2 = 800°C
t1 = 15°C
c = 460 Дж/кг×°С
Найти:
Q - ?
Решение:
Q = cm(t2-t1)
Q = 460 Дж/кг×°С × 200кг × (800°C - 15°C) = 460 Дж/кг×°С × 200кг × 785°C = 72220000Дж = 72220кДж

Ответ: 72220кДж

Answer 2

Calculating Heat Release when Cooling Steel Billet

To calculate the amount of heat released when cooling a steel billet from 800 degrees Celsius to 15 degrees Celsius, we can use the formula:

Q = c * m * (t2 - t1)

Where: - Q = heat released - c = specific heat capacity of steel - m = mass of the steel billet - t2 = final temperature (15 degrees Celsius) - t1 = initial temperature (800 degrees Celsius)

Using the given formula and the specific heat capacity of steel, we can calculate the heat released.

Calculation

Given: - m = 200 kg - t2 = 15°C - t1 = 800°C - Specific heat capacity of steel, c = 400 J/kg°C

Using the formula: Q = c * m * (t2 - t1)

Substituting the values: Q = 400 * 200 * (15 - 800) Q = 400 * 200 * (-785) Q = -62,800,000 J

Converting the result to kilojoules: Q = -62,800,000 J = -62,800 kJ

Therefore, the amount of heat released when cooling the steel billet from 800 degrees Celsius to 15 degrees Celsius is -62,800 kJ. The negative sign indicates that heat is being released during the cooling process.