A cast iron part weighing 300 g, having an initial temperature of 450, while cooling, gave the environment

A cast iron part weighing 300 g, having an initial temperature of 450, while cooling, gave the environment 64.8 kJ of heat. Determine the final temperature of the cast iron.

Task data: m (weight of cast iron part taken) = 300 g (0.3 kg); t2 (initial temperature) = 450 ºС; Q (heat transferred to the environment) = 64.8 kJ (64.8 * 10 ^ 3 J).

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

The final temperature of the cast iron part taken can be expressed from the formula: Q = M * m * (t2 – t1), whence t1 = t2 – Q / (M * m).

Calculation: t1 = 450 – 64.8 * 10 ^ 3 / (540 * 0.3) = 50 ºС.

Answer: The cast iron part taken will cool down to 50 ºС.