Question

a 250 g piece of brass at 95C is placed into 500g of water at 25C in an insulated container. Calculate the final equilibrium temperature (heat) of the brass in the insulated container.

Answer 1

Assume no heat loss to the container and use c_brass ≈ 0.380 J/g·°C, c_water = 4.184 J/g·°C.

Energy balance: m_b c_b (Tf − Tb) + m_w c_w (Tf − Tw) = 0, so

Tf = (m_b c_b Tb + m_w c_w Tw) / (m_b c_b + m_w c_w).

Plugging in:
Tf = (250·0.380·95 + 500·4.184·25) / (250·0.380 + 500·4.184)
= 61325 / 2187
≈ 28.04 °C.

Final equilibrium temperature ≈ 28.0 °C (both brass and water).