A point `A` is located at a distance `r = 1.5 m` from a point source of sound of frequency `600 H_(Z)`. The power of the source is `0.8 W`. Speed of sound in air is `340 m//s` and density of air is `1.29 kg//m^(3)`. Find at the point `A`, (a) the pressure oscillation amplitude`(Deltap)_(m)` (b) the displacement oscillation amplitude `A`.

Options

A. `10Nm^(-2)`
B. `15 Nm^(-2)`
C. `20 Nm^(-2)`
D. `5Nm^(-2)`

Answer

D

Explanation

`I=(P_(0)^(2))/(2rhoV)=P/(4pir^(2))=(P_(0)^(2))/(2rhoV)` where `P_(1) P_(0), V` are power, pressure amplitude and velocity respectively `rArr P_(0)=sqrt((PrhoV)/(2pir^(2)))=sqrt((50pixx1xx330)/(2pixx330))=5`