本题目来源于试卷: Physics Unit12: Sound，类别为 国际高中通用物理
[单选题]
At a distance of 15 m from a sound source the intensity levpf (2dsobnga o)m9xv+;)x p7 iel is 60 dB. Whl 5b,lh6njb( gat is the intensityll(bbng6 j 5,h level (in dB) at a point 2.0 m from 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:
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