I've been taught that the densities of air inside and outside the pipe differ slightly. Why should this happen. And let the densities vary, then during reflection from the ends, the reflected wave must have a slightly lesser amplitude than the incident wave and nodes won't be produced on superposition. But,we know standing waves form.Why?


marked as duplicate by knzhou, John Rennie, sammy gerbil, heather, BowlOfRed Aug 8 '16 at 20:19

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    $\begingroup$ This seems to be two separate questions. The first one is based on an incorrect premise -- I've never heard of such a statement. The second one is based on four incorrect premises. The densities don't vary, the reflected wave's amplitude would not be "slightly lesser" if this were the case, you can still have nodes even if the amplitude were lesser, and you can still have a standing wave without nodes. Finally, the question in the title seems to be different from either of the previous two, since you're claiming the mediums aren't the same. $\endgroup$ – knzhou Aug 7 '16 at 8:08
  • $\begingroup$ All of it is so confusing that you should just pick one question to ask, then explain exactly what you're thinking. $\endgroup$ – knzhou Aug 7 '16 at 8:09
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    $\begingroup$ @knzhou. You've mentioned the densities dont differ. Then why do waves reflect at the ends of the open organ pipe after all? $\endgroup$ – Amritansh Singhal Aug 7 '16 at 9:02
  • $\begingroup$ @AmritanshSinghal are you aware of acoustic impedance? Also remove the interference tag. $\endgroup$ – Yashas Aug 7 '16 at 10:15
  • $\begingroup$ There are already several questions on this site about standing waves in organ pipes. Have you read them? Probably your questions are addressed by one or other of them. If you have read them, please can you state how they fail to answer your question. ie What is different about your question? $\endgroup$ – sammy gerbil Aug 7 '16 at 12:52