S.O.S. Mathematics CyberBoard

Im slightly confused.. What waves do sound actually travel in?
In the first chapter of my physics book it mentions both.

Tranverse waves, where particles of a medium vibrate perpendicular to the wave propagation,

Longitudinal Waves, where particles vibrate parallel to the direction of wave propagation..

However it doesnt say why we need to both..


If a particle 'P' were suspended in air, and a speaker makes to the right of it. Would 'P' be moving left/right (longitudinal) or up/down (transverse)

thanks!!

Sound waves are LONGITUDINAL waves.

P would move left/right.

I see. Thank you.
Any idea why the textbook would introduce both types of waves in the 'Sound' Chapters?
thanks again.

Perhaps the book introduced it so to give a better idea about how loud the resulting noise was. Of course sound travels in longitudonal waves with the molecules of the medium vibrating and transferring the noise, but the idea of a transverse wave is more easier to think of when comparing the intensity of two different sounds, ie which is louder.

Question.
If a tree falls down in a forest and there is no-one there to see it or hear it, how do you know that it has actually fallen down?

OOPS
Last question slightly wrong,

It should be Does the tree make a sound?