An ambulance is generating a siren sound at a frequency of 2,400 Hz. The speed of sound is 345.0 m/s. If the ambulance is traveling at a velocity of 24.00 m/s away from the stationary observer, then what is the frequency of the siren perceived by the observer?
A) 2,375 Hz
B) 2,306 Hz
C) 2,266 Hz
D) 2,244 Hz
E) 2,210 Hz

Question

Quizplus · Accepted Answer

The frequency perceived by the observer can be calculated using the Doppler effect formula for sound: $ f' = f \frac{v}{v + v_s} $, where $ f' $ is the perceived frequency, $ f $ is the source frequency, $ v $ is the speed of sound, and $ v_s $ is the speed of the source relative to the observer. Plugging in the given values: $ f' = 2400 \frac{345}{345 + 24} = 2400 \frac{345}{369} \approx 2244 $ Hz.

An Ambulance Is Generating a Siren Sound at a Frequency