What amount of heat was released when cooling a cast-iron ingot weighing 32 kg, if its temperature

What amount of heat was released when cooling a cast-iron ingot weighing 32 kg, if its temperature changed from 1115 to 15 C?

Data: m (weight of the cast iron bar) = 32 kg; t1 (initial temperature of the cast iron bar) = 1115 ºС; t2 (temperature of the ingot after cooling) = 15 ºС.

Reference values: C (specific heat) = 540 J / (kg * K).

For the calculation, we assume that cast iron at 1115 ºС is in a solid state (the melting temperature range of various grades of cast iron is 1100 … 1300 ºС).

The amount of heat when cooling a cast iron bar: Q = C * m * (t1 – t2).

Calculation: Q = 540 * 32 * (1115 – 15) = 19 008 000 J ≈ 19 MJ.