With the complete combustion of dry wood, 50,000 kilojoules of energy were released. How much firewood was burned?

The amount of heat that will be released during the complete combustion of dry firewood is calculated using the formula:
Q = q * m, where Q is the released amount of heat (Q = 50,000 kJ = 50,000 * 10³ J), q is the specific heat of combustion of firewood (we take for dry firewood q = 15 * 10 ^ 6 J / kg), m – weight of firewood (kg).
Let us express and calculate the mass of burnt wood:
m = Q / q = 50,000 * 10³ / 15 * 10 ^ 6 ≈ 3.33 kg.
Answer: They burned 3.33 kg of dry firewood.