When a piece of copper, weighing 100 g, is cooled to 25 C, an amount of heat equal to 15 * 10 ^ 3 J is given off.

When a piece of copper, weighing 100 g, is cooled to 25 C, an amount of heat equal to 15 * 10 ^ 3 J is given off. To what temperature was the piece of copper heated?

Initial data: t (temperature to which a piece of copper was cooled) = 25 ºС; m (mass of a piece of copper) = 100 g = 0.1 kg; Q (the amount of heat given off by a piece of copper) = 15 * 10 ^ 3 J.
Reference data: С (specific heat of copper) = 400 J / (kg * K).
The amount of heat given off by a piece of copper can be represented in the form of the formula: Q = C * m * (tн – t), whence tн – t = Q / (C * m) and tн = Q / (C * m) + t.
Let’s calculate: tн = 15 * 10 ^ 3 / (400 * 0.1) + 25 = 375 + 25 = 400 ºС.
Answer: A piece of copper was heated up to 400 ºС.