匿名
匿名 發問於 科學及數學其他 - 科學 · 9 年 前

stationary wave

1. stationary wave is made by superposition of two progressive waves which can transmit energy, but stationary wave doesn't transmit energy. Why?

2. if all energy is confined in stationary wave, that is no energy transmitted, how can sound be heard using open tube/ closed tube?

更新:

then what is the energy conversion during the process of stationary wave, if energy is confined?

1 個解答

評分
  • 天同
    Lv 7
    9 年 前
    最佳解答

    1. In a stationary wave, e.g. a plucked guitar string, the vibration of the guitar string causes air surrounding it to oscillate, thus producing sound waves in the air. Energy is, in fact, transferred from the vibrating string to air.

    2. Similarly, in a an open tube (either open at both ends or at one end), the air at the mouth is set into oscillation by the stationary wave produced inside the tube. Thus trasmiting energy to the outside air. This is the reason why sound wave produced by plucking a guitar string or by blowing over an open tube dies down quickly if the guitar string is not plucked again or blowing over the tube ceases.

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