Relationship between wave propagation speed frequency

[mnb96]

Hello,
if we assume that the wave propagation-speed in a medium is v, does this imply that there is an "upper-bound" for the maximum frequency that a perturbation can produce?
Or are these totally unrelated quantities?

Thanks!

 

[Naty1]

You can't draw that conclusion...read the first few sentences here and think about light and sound waves for example:http://en.wikipedia.org/wiki/Wave_propagation

 

[mnb96]

ok...I am still confused.

1) First of all: is it true that any medium, for example the air, can "vibrate" at any speed, although the vibration will propagate only at a certain speed (e.g. the speed of sound)?

2) Even if point 1) is correct, think about a source-receiver scenario. A source emits a wave by perturbing the medium at an extremely high frequency. However the vibration propagates through the medium extremely slowly. The receiver will "record" a much lower frequency than the one emitted.

 

[nasu]

ok...I am still confused.

2) Even if point 1) is correct, think about a source-receiver scenario. A source emits a wave by perturbing the medium at an extremely high frequency. However the vibration propagates through the medium extremely slowly. The receiver will "record" a much lower frequency than the one emitted.

The receiver will record the same frequency, only much later, due to the slow propagation.
The propagation speed determines the delay between the signal emission and reception.