Question Number 35881 by NECx last updated on 25/May/18
$${A}\:{train}\:{travelling}\:{at}\:\mathrm{30}{m}/{s}\:, \\ $$$${approaching}\:{a}\:{stationary}\:{observer} \\ $$$${emits}\:{a}\:{tone}\:{at}\:{a}\:{frequency}\:{of}\:\mathrm{480}{Hz}. \\ $$$${If}\:{the}\:{speed}\:{of}\:{sound}\:{is}\:\mathrm{330}{m}/{s}, \\ $$$${determine}\:{the}\:{frequency}\:{of}\:{the} \\ $$$${note}\:{the}\:{observer}\:{hears}. \\ $$
Commented by tanmay.chaudhury50@gmail.com last updated on 25/May/18
Answered by tanmay.chaudhury50@gmail.com last updated on 25/May/18
$${f}^{'} ={f}\frac{{v}}{{v}−{v}_{{s}} }=\mathrm{480}×\frac{\mathrm{330}}{\mathrm{330}−\mathrm{30}} \\ $$$${f}'=\frac{\mathrm{480}×\mathrm{330}}{\mathrm{300}} \\ $$$$=\mathrm{48}×\mathrm{11}=\mathrm{528} \\ $$
Commented by NECx last updated on 28/May/18
$${Thank}\:{you}\:{Tanmay}\:{sir} \\ $$