Longitudinal waves?

[onedirection]

Random question with these

1) Why can't they be polarized
2) What would constructive/destructive interference look like with them since they don't look like transverse waves
3) What would the standing frequency/are nodes possible with these?

I'm just getting the idea that longitudinal waves look like
||||||||| <---look like this as the wave propagates forward

while transverse ones are the sin functions one

Do longtitudinal waves also potentially a sine function

maybe i'm just applying the whole perpendicular to the advancing wavefront idea of the transverse wavefront to mean it's graph when the two are mutually exclusive

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[sudev]

Right. Mechanical waves are either transverse or longitudinal. The medium is displaced perpendicular to the wave direction for transverse waves, and parallel for longitudinal ones. The diagram (...?) you've typed as a longitudinal wave is along the right track, but remember displacement of the medium implies both compression (lines closer together) and rarefaction (fancy word for stretched out):

----> ||| | | | | | | | | | ||| | | | | | | | | | ||| ---->​

For sound waves, these correspond to variations in pressure, since the medium is that of air. Don't get confused when representing this stuff graphically. Both wave types (and plenty of other forms of periodic motion) can be modeled as sine waves. But be careful-for transverse waves, the sine wave represents the actual perpendicular displacement (typically as a function of time) and is therefore a crude representation of what you would actually see if you could observe one, like a wave on a string. For longitudinal waves, however, the sine wave may represent the pressure variation (aka horizontal displacement) as a function of time, as in the case of sound waves. Still periodic? Yes. Still a sine wave? Yes. But, don't be fooled into thinking that, like in graphs of transverse waves, it represents what a sound wave would actually look like in terms of how it propagates in 2d or 3d space.

Assuming this is MCAT-prep related, random questions #1 and #2 are abstract and beyond the scope of the basic knowledge needed. Longitudinal waves propagate parallel to the wavefront (1-D), and therefore do not have additional axes with which to vary their angle of propagation, as with transverse waves. Constructive and destructive interference would simply be where the regions of rarefaction and compression overlap along two superimposed wavefronts, and graphing these variations will produce everything you need (relevant to the test) to identify wavelengths, frequencies, periods, nodes, etc to answer random question #3 without having to visualize them. 👍