Wave Momentum
The physical forward momentum carried by a transverse wave along a string is conveyed by a secondary longitudinal wave [391].
A less simplified wave equation which
supports longitudinal wave momentum is given by [391, Eqns. 38ab]
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(B.40) |
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(B.41) |
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(B.42) |
where
![$ \xi$](http://www.dsprelated.com/josimages_new/pasp/img2268.png)
![$ \eta$](http://www.dsprelated.com/josimages_new/pasp/img922.png)
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(B.43) |
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(B.44) |
(See also Eq.
![$ \,$](http://www.dsprelated.com/josimages_new/pasp/img196.png)
![$ SY\eta^\prime\eta^{\prime\prime}$](http://www.dsprelated.com/josimages_new/pasp/img3043.png)
Physically, the rising edge of a transverse wave generates a longitudinal displacement in the direction of wave travel that propagates ahead at a much higher speed (typically an order of magnitude faster). The falling edge of the transverse wave then cancels this forward displacement as it passes by. See [391] for further details (including computer simulations).
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Non-Stiff String