Question

Sound travels 4x faster in water than air, WHY ?

Answer 1

Sound travels 4x faster in water than air, WHY?

General equation for speed of sound:

$$c = \sqrt {\frac {K}{\rho}}$$

Where $\rho$ – density, $K$ – bulk modulus.

$$\frac {c _ {w}}{c _ {a}} = \sqrt {\frac {K _ {w} \rho_ {a}}{\rho_ {w} K _ {a}}}$$

At $20{}^{\circ}\mathrm{C}$:

$$\frac {c _ {w}}{c _ {a}} = \sqrt {\frac {2 . 2 * 1 0 ^ {9} P a * 1 . 2 k g / m ^ {3}}{1 0 0 0 k g / m ^ {3} * 1 . 4 2 * 1 0 ^ {5} P a}} \cong 4. 3$$

Sound travels faster in water than in air due to relations between water's and air's parameters.