Question

The frequency of the siren of an ambulance is 900 Hz and is approaching you. You are standing on a corner and observe a frequency of 960 Hz. What is the speed of the ambulance (in mph) if the speed of sound is v

Answer 1

`v_(s)`= 47.53 mph

Step-by-step explanation:

by using Doppler Effect

the frequency f' is the observed frequency by the observer :

by using relations

`f' =[(v)/(v-v_(s))]* f\\`

where v is speed of sound in medium and
`v_(s)` is speed of source ( ambulance)

on solving above equation we get

`v_(s) = ((f' -f)v)/(f')`

substitute the values we get

`v_(s) = (( 960 -900)(340))/(960)\\v_(s) = 47.53 mph`