Question

An ambulance is driving towards the hospital at a velocity 94.0 km/h and emitting a steady 878-Hz sound from its siren. The sound reflects off the front of the hospital and is received by the same ambulance. In addition to it's own siren, the ambulance hears a shifted tone from the reflection at what frequency

Answer 1

The frequency is 1022.68 Hz

Step-by-step explanation:

According the Doppler`s effect, the frequency is:

`f=f_(o) ((v+v_(o))/(v-v_(o) ) )`

Where

fo = 878 Hz

v = velocity of sound = 343 m/s

v₀ = 94 km/h = 26.11 m/s

Replacing:

`f=878((343+26.11)/(343-26.11) )=1022.68Hz`

Answer 2

Complete Question

An ambulance is driving towards the hospital at a velocity 94.0 km/h and emitting a steady 878-Hz sound from its siren. The sound reflects off the front of the hospital and is received by the same ambulance. In addition to it's own siren, the ambulance hears a shifted tone from the reflection at what frequency? The speed of sound on this day is 343 m/s

Answer:

The frequency is
`f =1022.0 \ Hz`

Step-by-step explanation:

From the question we are told that

The velocity of the ambulance
`v = 94.0km/h = 94 *(1000 m)/(3600s) = 26 \ m/s`

The frequency emitted is
`f_0 = 878 \ Hz`

The illustration of the process is shown on the first uploaded image

The frequency at the hospital wall due to Doppler's effect is mathematically repented as

`f_1 = f_o [(v)/(v-v_o) ]`

Now as seen the frequency at the ambulance is mathematically represented as

`f = f_1 [(v+v_o)/(v) ]`

Now substituting for
`f_w`

`f = f_o [(v+v_o)/(v-v_o) ]`

Substituting value

`f = 878 * (343 +26)/(343 -26)`

`f =1022.0 \ Hz`