Question

A factory siren emits a sound at 900hz.what frequency will be heard by the driver of a car traveling at 100km.h away from the factory?
Help me please!
Vd=100,000m/1h * 100000m/3600s=27.8 m/s
= Velocity of driver.

Fd = ((Vs-Vd)/(Vs+Ve))*Fe
Fd = ((343-27.8)/(343+0))*900Hz
Fd = (315.2/343) * 900 = 827 Hz = Freq.
heard by driver.

Vs = Velocity of sound in air.
Ve = Velocity of the sound emitter
(siren).
Fe = Freq. emitted.

Related Questions

A siren mounted on the roof of a firehouse emits sound at a frequency of 900 Hz. A steady wind is bl... a police siren emits a sinusoidal wave with frequency f=300hz.the speed of sound is 340ms. find the... A police car siren emits a sound wave with a frequency fs = 400 Hz and it is moving toward... A siren emits a sound of frequency 1200 kHz. With which frequency is it received by a car moving at...