Question

A source emits sound with a frequency of 18,002 Hz. Both it and an observer are moving toward each other, each with a speed of 130 m/s. What frequency (in Hz) does the observer hear

Answer 1

The frequency heard by the observer is 24,830.35 Hz.

Step-by-step explanation:

Given;

frequency of the source, Fs = 18,002 Hz

speed of the source, Vs = 130

speed of sound in air, V = 343 m/s

Apply Doppler effect, as the source and the observer move closer to each other, the frequency heard by the observer increases because of decrease in distance.

`f_s = f_o[(v)/(v + v_s) ]\\\\`

where;

f₀ is the frequency heard by the observer

`f_s = f_o[(v)/(v + v_s) ]\\\\18,002 = f_o[(343)/(343 + 130) ]\\\\18,002 = f_o(0.725)\\\\f_o = (18,002)/(0.725) \\\\f_o = 24,830.35 \ Hz`

Therefore, the frequency heard by the observer is 24,830.35 Hz.