Ch. 17 Introduction - University Physics Volume 1 | OpenStax
Sound: L-waves
Sound - hearing
(20 - 20,000 Hz in air)
Particle is not travelling just oscillate to transfer the wave
v = $\sqrt {\frac {F_t} \mu}$
Speed of sound in air → ~340 m/s
| Medium | v (m/s) |
|---|---|
| Gases at 0 °𝐶 | |
| Air | 343 |
| Carbon dioxide | 259 |
| Oxygen | 316 |
| Helium | 965 |
| Hydrogen | 1290 |
| Liquids at 20°𝐶 | |
| Ethanol | 1160 |
| Mercury | 1450 |
| Water, fresh | 1480 |
| Sea Water | 1540 |
| Human tissue | 1540 |
| Solids (longitudinal or bulk) | |
| Vulcanized rubber | 54 |
| Polyethylene | 920 |
| Marble | 3810 |
| Glass, Pyrex | 5640 |
| Lead | 1960 |
| Aluminum | 6420 |
| Steel | 5960 |
db = 10 log10 (I/I0)
$$ dB = 10\ log_{10} (\frac I {I_0}) $$
$$ f_{beat} = |f2-f1| $$
$$ y(t)=2A cos(2\pi f_{avg}t)cos(2\pi (\frac {|f2-f1|} 2)t) $$