[填空题]
A 120-g insulated alumi1mv)jw*fdx3-/ c mjio9) ha opnum ci/z+ilwr, g9rup at 15$^{\circ}\,C$ is filled with 140 g of water at 50$^{\circ}\,C$. After a few minutes, equilibrium is reached.
(a) Determine the final temperature, $^{\circ}\,C$
(b) estimate the total change in entropy. $J/K$
