- #1

Biker

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2) The power of a sound wave, I have looked on the internet for derivations and all of them used calculus which is a quite expected thing so I skipped it because I still didnt take integration. However I found a proof posted by someone it was like this:

##E = 0.5 ~ K ~~A^2##

Where E represents the energy of the wave.

He then used

##f = \frac{1}{2\pi} (\frac{k}{m})^{0.5}##

to get'

## I = 2 \pi^2 v p f^2 A^2 ##

Which is actually the correct form. But this derivation doesn't make sense at all physically. To me it is just like plug and chug because the system requires integration to be analysed. However, the weird thing that it gave a correct equation which might be coincidence but not really sure if math coincides in this situation. I would see this working if actually every molecule had the same energy and it is equal to E above.

3) Is the speed of waves in medium only constant because we modeled the medium as springs and it is as always a good approximation to the real world? and that the speed would change if the medium behaved differently?

4 ) How come air molecules can behave so nicely and harmonically while the wave depend on molecules bumping into each other? Isn't there is some motion due to temperature and what so ever? effects are negligible? Is there a graphical reasoning how air molecules spread a wave in 3d because the forces between gases are weak and again it will depend on bumping. It is just seems more of probabilistic than organised. A model with a springs between air molecules would make sense but not really sure about real world. The problem is I care too much about graphical reasoning, The mathematics isn't hard but the Imagining part is.

Are the forces between gases strong enough to actually to force a gas into a particular shape?Thank you. :D