Question

The faintest sound the human ear can detect at a frequency of ` kHz` (for which ear is most sensitive) corresponds to an intensity of about `10^(-12)w//m^(2)`. Assuming the density of air `cong1.5kg//m^(3)` and velocity of sound in air `cong300m//s`, the pressure amplitude and displacement amplitude of the sound will be rspectively ____`N//m^(2)` and ____`m`.
A. `3xx10^(-5) Pa`
B. `2xx10^(-5) Pa`
C. `5xx10^(-5) Pa`
D. `4xx10^(-5) Pa`

Answer 1

Correct Answer - A
`I=(P_(m)^(2))/(2rhoV)`
`10^(-12)=(P_(m)^(2))/(2(1.5)(300))`
`P_(m)=3xx10^(-4) P_(a)`