What amount of heat will a brick kiln made of 500 bricks give when it cools down from 70 to 20 ° C? The mass of one brick is 4 kg.

Data: N (number of bricks from which the furnace is built) = 500 bricks; t1 (furnace temperature before cooling) = 70 ºС; t2 (final oven cooling temperature) = 20 ºС; m1 (mass of one brick) = 4 kg.
Reference data: C (specific heat capacity of a brick) = 880 J / (kg * ºС).
1) The total mass of the bricks from which the furnace is built: m = N * m1 = 500 * 4 = 2000 kg.
2) The amount of heat that the brick oven will give: Q = C * m * (t1 – t2) = 880 * 2000 * (70 – 20) = 880 * 2000 * 50 = 88,000,000 J (88 MJ).