What mass of coal must be burned in order to obtain the same amount of heat that

What mass of coal must be burned in order to obtain the same amount of heat that is released during the combustion of 20 tons of kerosene?

Initial data: m1 (mass of burned kerosene) = 20 tons.

Reference data: q1 (specific heat of combustion of kerosene) = 46 * 10 ^ 6 J / kg; q2 (specific heat of combustion of coal) = 27 * 10 ^ 6 J / kg.

SI system: m1 = 20 t = 20 * 10 ^ 3 kg.

The mass of coal that needs to be burned can be determined from the equality: Q1 (combustion of kerosene) = Q2 (combustion of coal) = q1 * m1 = q2 * m2, whence m2 = q1 * m1 / q2.

Let’s calculate: m2 = 46 * 10 ^ 6 * 20 * 10 ^ 3 / (27 * 10 ^ 6) = 34 * 10 ^ 3 kg or 34 tons.