作者NewFreedom (反社会)
看板Physics
标题Re: [转录]Re: [问题] 请问声波在开口管为何会反射？
时间Fri Jul 3 23:10:43 2009
我把原文书的解释打上来好了
Sound is a pressure wave, and a compression region of the sound wave is
constrained by the sides of the pipe as long as the region is inside the pipe.
As the compression region exits at the open end of the pipe, the constraint of
the pipe is removed and the compressed air is free to expand into the
atmosphere. Thus, there is a change in the "character" of the medium between
the inside of the pipe and the outside even though there is no change in the
"material" of the medium. This change in character is sufficient to allow
some reflection.
大意就是管内的密部会被管壁所拘束,管外不会,虽然管内外是相同的空气,
但因前述环境的不同,可造成反射.
至於此现象的详细参数,是压力or声速不同等等,我就不会了,请会的人解答指正 ^^
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1F：推 alenbe:感谢提供教科书的说法，上一篇提到的补偿性波，我也不懂 :P 07/03 23:20
2F：推 denisck123:所以基本上就跟我上篇说的是类似的 07/04 00:05
3F：→ denisck123:管口内疏密波碰到管口外时可看成细绳跟粗绳的想法 07/04 00:07
4F：→ denisck123:也就像是介质(环境)不同一般 所以会有反射跟透射罗 07/04 00:07