Question

A 2640-Hz sound source is moving at 15.0m/s toward a stationary observer. What is the frequency heard by the observer if the speed of sound is 343 m/s?

Answer 1

Answer:

The frequency heard by the observer is 2760.73 hertz.                 Explanation:

Frequency of source, f = 2640 Hz

Velocity of source, $v_s=15\ m/s$

The speed of sound, v = 343 m/s

Let f' is the frequency heard by the observer. According to Doppler's effect, the frequency of the observer is given by :

$f'=\dfrac{fv}{v-v_s}$ (as the source is moving towards observer)

$f'=\dfrac{2640\times 343}{343-15}$  

f' = 2760.73 Hz

So, the frequency heard by the observer is 2760.73 hertz. Hence, this is the required solution.