Sound and frequency

[SereneAurora]

If frequency remains constant when waves change mediums. And velocity of a wave increases directly with the density of the material it's traveling through. Then is the only thing that is actually being altered is wavelength? This concept confuses me sometimes.... I get these questions right the majority of time, but have a hard time visualizing. Google isnt much help because i cant find a good animation.

Also, When's a situation when frequency can change??*

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[NickNaylor]

Frequency doesn't change because that would result in a change in energy (E = hf), which can't happen randomly. In most problems you're assuming that a beam of light doesn't lose energy when it's changing media.

I guess it doesn't really matter how you think of it, but technically the velocity of the wave is what's changing. Since the frequency must remain constant (in the context of MCAT problems), the wavelength must change as the speed changes (by f = v / lambda).

 

[Flamen04]

I guess it doesn't really matter how you think of it, but technically the velocity of the wave is what's changing. Since the frequency must remain constant (in the context of MCAT problems), the wavelength must change as the speed changes (by f = v / lambda).

Yep, the speed of a wave is directly proportional to its wavelength. The larger the wavelength, the faster the speed (and vice versa). Therefore, when a wave changes mediums, it's wavelength is also changed.

 

[SN2ed]

Thread moved. These types of questions belong in the Study Q&A forum.