How much heat is required to heat 3 kg of cast iron from 10 C to 90 C?

Initial data: m (mass of cast iron) = 3 kg; t0 (temperature of cast iron before heating) = 10 ºС; t (final heating temperature of cast iron) = 90 ºС.

Reference data: C (specific heat capacity of cast iron) = 540 J / (kg * K).

The required amount of heat for heating cast iron is determined by the formula: Q = C * m * (t – t0).

Let’s calculate: Q = 540 * 3 * (90 – 10) = 540 * 3 * 80 = 129 600 J or 129.6 kJ.

Answer: To heat 3 kg of cast iron, 129.6 kJ of heat is required.