How much energy will be released during the complete combustion of dry firewood weighing

How much energy will be released during the complete combustion of dry firewood weighing 3 kg and charcoal weighing 7 kg?

Initial data: m1 (dry wood mass) = 3 kg; m2 (mass of charcoal) = 7 kg.

Reference data: q1 (specific heat of combustion of dry wood) = 10 * 10 ^ 6 J / kg; q2 (specific heat of combustion of charcoal) = 34 * 10 ^ 6 J / kg.

The released amount of energy during fuel combustion: Qx = qx * mx.

1) Q1 = q1 * m1 = 10 * 10 ^ 6 * 3 = 30 * 10 ^ 6 J = 30 MJ.

2) Q2 = q2 * m2 = 34 * 10 ^ 6 * 7 = 238 * 10 ^ 6 J = 238 MJ.

Answer: When burning firewood, 30 MJ of energy will be released, charcoal – 238 MJ.