Question

For plane waves in the air of frequency 1000 Hz and the displace amplitude `2xx10^(-8)m`, deduc (i) the velocity amplitude, and (ii) the intensity. (Take p= 1.3 kg//m^(3),c=340 m//s)`

Answer 1

`vmax("velocity amplitude")=aomega`
`:.v_(max)=2xx10^(-8)xx(2pixx1000)=1.3xx10^(-4) m//s`
`I=(1)/(2)pa^(2)omega^(2)c=(1)/(2)pv^(2)_(max)c`
`implies I=(1)/(2)xx1.3(1.3xx10^(-4))^(2)xx340=3.7xx10^(-6) W//m^(2)`