gc textbook chapter 12 Sound (id: cdc564d94)

本题目来源于试卷: gc textbook chapter 12 Sound，类别为 通用国际物理

[填空题]
Workers around jet aircraft tyc r8 x46wfvh8ypically wear protective devv mo)4hh(xm ()z2bvxl ices over their ears. Assume that the sound level of a jet airplane engine, at a distance of 30 m, is 140 dB, and that the average human ear has an effective radius of 2.0 cm. What would be the power intercepted by an unprotected ear at a distance of 30 m from a jet airvo2 h)h(zbmvm 4l(xx)plane engine?    W

参考答案: 0.13±2%


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