Question

Hi, Can anyone help me? I don't understand.

A car horn has a frequency of 448 Hz when the car is stationary. If the car approaches a stationary recorder at a speed of 19.0 m/s, what frequency does the device record if the temperature is 20°C? What frequency does the device record after the car passes by?

**SHOW CALCULATIONS, PLEASE!

Answer 1

The frequency recorded by the device after the car passes by at the given speed is 474.27 Hz.

Observed frequency recorded by the device

The frequency recorded by the device is determined by using the following formula for doppler effect.

$f_o = f_s(\frac{v + v_0}{v- v_s} )$

where;

• v is speed of sound at 20°C = 343 m/s
  vo is speed of the observer = 0
• vs is the speed of the sound towards the observer = 19 m/s
• fs is the source frequency
• fo is the observed frequency

$f_o = 448(\frac{343 + 0}{343-19} )\\\\f_0 = 474.27 \ Hz$

Thus, the frequency recorded by the device after the car passes by at the given speed is 474.27 Hz.

Learn more about frequency here: https://brainly.com/question/10728818

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