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What exactly determines the energy of a wave? the intensity? or the frequency?

  1. Feb 20, 2012 #1
    I am taking AS level Physics rite now, and wanted to know what exactly determines the energy of a wave. Well since I have recently learn of stationary waves(sound waves) being standing. I know that they are formed by the superimposition of the reflected waves on the incident waves. This causes the amplitude to cancel out, and become zero. So intuitively I guess the frequency decides a waves energy, because if intensity did, then in a stationary wave, the amplitudes canceling out would make the intensity nil as well(I=κA6^2), so this will make the sound stop, which it clearly does not.
    So is this reasoning right?
  2. jcsd
  3. Feb 20, 2012 #2
    It depends on the context actually. In terms of mechanical waves, for example a water wave ripple in a pond, more energy is carried by the wave for high amplitudes. Photons are another type of wave, but they carry energy in their frequency. A sound wave is a mechanical wave, and so the amplitude determines the energy of the wave.
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