What mass of kerosene needs to be burned in order to heat 10 tons of cast iron by 10 degrees due to the released heat?

Given:

m = 10 tons = 10000 kilograms – the mass of cast iron;

dt = 10 ° Celsius – the temperature to which the cast iron must be heated;

c = 540 J / (kg * C) – specific heat capacity of cast iron;

q = 40.8 MJ / kg = 40.8 * 10 ^ 6 Joule / kilogram is the specific heat of combustion of kerosene.

It is required to determine M (kilogram) – what mass of kerosene needs to be burned in order to heat the cast iron to a temperature equal to dt.

To heat cast iron, energy will be required equal to:

Q = c * m * dt = 540 * 10000 * 10 = 540 * 100000 = 54000000 Joules.

Then, to determine the mass of kerosene, you must use the following formula:

M = Q / q = 54000000 / (40.8 * 106) = 54 / 40.8 = 540/408 = 1.3 kilograms (the result has been rounded to one decimal place).

Answer: you need to burn kerosene weighing 1.3 kilograms.