A 0.40kg block of brass at 180∘C is quickly transferred into an insulated cup that contains 0.20kg of water at 20∘C. The specific heat of brass is 380Jkg−1K−1 and the specific heat of water is 4.18×103Jkg−1K−1. After sufficient time, the system reaches a uniform final temperature.
Assume the cup and its lid are perfect thermal insulators and have negligible heat capacity.
(1) Qualitatively describe the direction of energy transfer between the brass block and the water until thermal equilibrium is achieved. In your explanation, include the sign of the temperature changes for both substances.
(2) Without performing a numerical calculation, explain whether the final equilibrium temperature will be closer to 20∘C or 180∘C. Support your answer by referring to the relative masses and specific heats of the two substances.