Physics Unit12: Sound (id: a183251a8)

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]
Sonar is used to determine *v2b e*w il( 5zoaoia2the speed of an object. k.lb-42+lxn- y eidfz A 40-kHz signal is sent out, and a 42-kHz signal is returned. Assume th+x-bfklndy24 - z.le ie speed of sound is 345 m/s. How fast is the object moving?

A. 6.9 m/s
B. 8.4 m/s
C. 331 m/s
D. 347 m/s


参考答案:  B


本题详细解析: 暂无

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