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 sour:tvx4c p /9yjejd v ofg3n x(:/xr4lo*ce the inte6a+ (cmfc r i4sv-;ijznsity level is 60 dB. What is the intensity level (in dB) at 6j(c+4isa i;-fmrvc z 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:
暂无
|