Question

The faintest sound an ear can hear (20 micro-pascals) is roughly ______ times smaller than atmospheric pressure at sea level.

Answer 1

Answer: $5.06\times10^{9}$

At sea level, there is one standard atmospheric pressure which is equal to 101.325 kilopascals.

The pressure of faintest sound that a human ear can hear is 20 micro-pascals.

taking the ratio of two:

$\frac {101.325 kilopascals. }{20 micropascals} = \frac {101.325 \times 10^{3}Pa}{20 \times 10^{-6}Pa}$

$=5.06\times10^{9}$

Hence, the atmospheric pressure at sea level is $5.06\times10^{9}$ times greater than the faintest sound that a human ear can hear.