7. A 70-kg log falls from a height of 25 m into a lake. Suppose the log, the lake, and the air are all at 300 K. What is the change in the entropy of the Universe for this process, assuming that all of the log's potential energy is converted into heat?
(A) 57 J/K
(B) 29 J/K
(C) 13 J/K
(D) 7 J/K
(E) 0 J/K
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統計: 尚無統計資料
統計: 尚無統計資料
詳解 (共 1 筆)
#7439733
所以看到這題只要想到一個公式就是宇宙的商增加量的公式會等於

然後代入題目給的數值即可求出

而又因為機械能轉換成熱能的話是不可逆過程,所以總商不會是0
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