As a train pulls out of the station going 45 m/s it blasts its horn, what is the frequency heard by the train if the passengers still at the station are hearing 373 Hz?

1 answer

To determine the frequency heard by the train, we can use the formula for the Doppler effect:

f' = f(ct + v) / (ct + vs)

Where:
f' is the frequency heard by the train
f is the frequency heard by the stationary observers (passengers at the station)
c is the speed of sound in air (assumed to be 343 m/s)
t is the time (which doesn't affect the frequency)
v is the velocity of the train (45 m/s)
s is the speed of sound in air (343 m/s)

Plugging in the values, we have:

f' = 373(343 + 45) / (343 - 45)
f' = 373(388) / (298)
f' ≈ 486.94 Hz

Therefore, the frequency heard by the train is approximately 486.94 Hz.