Question

The car shown below is approaching the observer at a speed of 40 m/s. The car honks its horn at a frequency of 1,000 Hz, and the speed of sound in air is 340 m/s. What is the frequency that the observer will hear?

Answer 1

observed frequency F = 1133.33 Hz

Step-by-step explanation:

given data

car speed = 40 m/s

horn frequency = 1,000 Hz

speed of sound in air = 340 m/s

solution

We use here Doppler's Effect formula for unknown frequency that is

observed frequency F =
`((V + Vl) * Fs)/((V - Vs))` ...................1

here v is velocity of sound in air and Vl is velocity of observer and and Vs is velocity of source and Fs is actual frequency

put here value and we will get

observed frequency F =
`((340 + 0) * 1000)/((340 - 40))`

observed frequency F = 1133.33 Hz