本题目来源于试卷: 美国2021年物理杯赛真题 PHYSICS BOWL 2021，类别为 美国物理杯赛(Physics Bowl)
[单选题]
An engine absorbs heat at a temperature of $727 ^\circ C$ and exhausts heat at a temperature of $527 ^\circ C$. If the engine operates at maximum possible efficiency, for 2000 J of heat input, the amountof work the engine performs is most nearly
A. 400 J
B. 1450 J
C. 1600 J
D. 2000 J
E. 2760 J
参考答案: A
本题详细解析:
Efficiency is:$e=1-\frac{T_L}{T_H} (T in Kelvins)=0.8; (0.8)(2000J)=400J$
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