With the complete combustion of coal in the furnace, 945 MJ of energy were released. What is the mass of coal?

Given:

Q = 945 MJ – the amount of energy released during the complete combustion of coal in the furnace;

q = 2.7 * 10 ^ 7 Joule / kilogram – specific heat of combustion of coal.

It is required to determine m (kilogram) – what is the mass of burnt coal.

Let’s convert the units of measurement of energy into the SI system:

Q = 945 MJ = 945 * 10 ^ 6 Joules.

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

Q = q * m, from here we find that:

m = Q / q;

m = 945 * 10 ^ 6 / (2.7 * 10 ^ 7) = 350 * 10 ^ 6 – 7 = 350 * 10 ^ -1 = 35 kilograms.

Answer: the mass of the burnt coal is 35 kilograms.