How to Calculate Distance Using the Doppler Effect

In summary, the problem involves a physics student dropping a vibrating tuning fork down an elevator shaft with a temperature of 20 °C. The student hears a frequency of 392 Hz and the tuning fork has a frequency of 421 Hz. Using the Doppler equation, the student calculates the velocity of the source to be 25.38 m/s, but is unsure how to apply it to the problem. The question asks for the distance the tuning fork has fallen and hints at the relationship between velocity and falling objects.
  • #1
leinad0213
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0

Homework Statement



A physics student drops a vibrating 421 Hz tuning fork down the elevator shaft of a tall building. The temperature in the shaft is 20 °C. When the student hears a frequency of 392 Hz, how far has the tuning fork fallen?

fS = 421 Hz
fL = 392 Hz
VSOUND = 343 m/s

Homework Equations



Doppler Equation: fL = fs(VSOUND + Vlistener)/(VSOUND + VSource)

The Attempt at a Solution



I solved for the velocity of the source and got 25.38 m/s but I don't really get how I would apply it to this problem. If only I had time.
 
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  • #2
How does the velocity of a dropped object incresase?
 

1. What is the Doppler Effect?

The Doppler Effect is the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source. It is commonly observed in sound waves, such as the change in pitch of a siren as an ambulance passes by.

2. How does the Doppler Effect work?

The Doppler Effect occurs because the motion of the observer causes a change in the distance between the source of the wave and the observer, resulting in a perceived change in frequency. If the observer is moving towards the source, the frequency appears higher, while if the observer is moving away from the source, the frequency appears lower.

3. How is the Doppler Effect used in science?

The Doppler Effect is used in many different fields of science, including astronomy, meteorology, and medical imaging. In astronomy, it helps determine the motion of stars and galaxies. In meteorology, it is used to track the movement of storms. In medical imaging, it is used in ultrasound to measure blood flow in the body.

4. What is the formula for calculating the Doppler Effect?

The formula for calculating the Doppler Effect is: fobs = fsource * (v +/- vobs) / (v +/- vsource), where fobs is the observed frequency, fsource is the source frequency, v is the speed of the wave, vobs is the speed of the observer, and vsource is the speed of the source.

5. What are some real-world applications of the Doppler Effect?

The Doppler Effect has many practical applications, including radar technology, speed guns, and sonar. It is also used in the study of dark matter and to measure the expansion of the universe. In addition, the Doppler Effect is used in the design of musical instruments to create different pitches and in the development of noise-cancelling headphones.

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