本题目来源于试卷: Physics Unit12: Sound，类别为 通用国际物理
[单选题]
At a distance of 15 m from a sound :c :1hzrhxg(pq /q7g usource the intensity lea 4x,br8pzl3 znm,tle*j ,7b bvel is 60 dB. What is the intensity level (in dB) at a point 2.0 m fbxzbm e*,jat8l 7,lrpz34 ,nbrom the source? Assume that the source radiates equally in all directions.
A. $55.7 \; dB$
B. $57.5 \; dB$
C. $75.5 \; dB$
D. $77.5 \; dB$
参考答案: D
本题详细解析:
暂无
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