Frequency spectrum in Doppler effect

In summary, the conversation discusses using the Doppler effect to determine the speed of sound in a circular motion with a stationary source and moving observer. The speaker mentions using Vernier software and obtaining two graphs of sound pressure against time. They also mention trying two different frequencies and a radius of 40cm. The question about FFT analysis is posed, with the response that it may not be helpful for a pure tone source.
  • #1
yulija
3
0

Homework Statement


I have been investigating the Doppler effect in a circular motion with a stationary source and moving observer (however the main aim is to determine the speed of sound in the end). Using Vernier software - Logger Pro - I have obtained two graphs of the sound pressure against time.

I may also use FFT analysis and get a frequency spectrum but I am not sure what I can use it for. How can in help?

I tried two different frequencies:
f1 = 3000Hz
f2 = 1000Hz

And the radius of the circle was 40cm.

Homework Equations


observer-moving-stationary-source.png
observer moving towards the source
observer-away-from-stationary-source.png
observer moving away from the source
 
Last edited:
Physics news on Phys.org
  • #2
If your source is more-or-less a pure tone, I don't see how FFT will help. It will still be a single frequency received at any instant.
Was that your only question?
 

1. What is the frequency spectrum in Doppler effect?

The frequency spectrum in Doppler effect refers to the range of frequencies that are observed when a source of sound or light is moving relative to an observer. This spectrum includes both the original frequency of the source and the shifted frequencies due to the Doppler effect.

2. How does the frequency spectrum change in Doppler effect?

The frequency spectrum changes in Doppler effect because the relative motion between the source and observer causes the wavelengths of the waves to either lengthen or shorten. This results in a shift in the observed frequency, with higher frequencies being observed if the source is approaching the observer, and lower frequencies being observed if the source is moving away from the observer.

3. Can the frequency spectrum in Doppler effect be used to determine the speed of the source?

Yes, the frequency spectrum in Doppler effect can be used to determine the speed of the source by measuring the amount of frequency shift and using the Doppler formula. This formula takes into account the speed of sound or light, the original frequency of the source, and the observed frequency to calculate the speed of the source relative to the observer.

4. What factors affect the frequency spectrum in Doppler effect?

The frequency spectrum in Doppler effect is affected by the relative velocity between the source and observer, the speed of sound or light, and the original frequency of the source. It can also be affected by the medium through which the waves are traveling, as well as any obstructions or reflections that may occur.

5. What are some real-world applications of the frequency spectrum in Doppler effect?

The frequency spectrum in Doppler effect has many practical applications, including in radar and sonar technologies for detecting the speed and location of moving objects. It is also used in medical imaging techniques like ultrasound, as well as in astronomy for measuring the movement of celestial objects. Additionally, the Doppler effect is utilized in traffic speed cameras and speed guns used by law enforcement.

Similar threads

Range of frequency heard by observer related to Doppler effect
    • Introductory Physics Homework Help
Replies
8
Views
200
The relativistic Doppler effect
    • Introductory Physics Homework Help
Replies
5
Views
1K
Understanding the Doppler Effect: Solving the Bat Problem
    • Introductory Physics Homework Help
Replies
1
Views
3K
Changing of frequencies in the Doppler effect
    • Introductory Physics Homework Help
Replies
3
Views
796
Doppler effect and beat frequency
    • Introductory Physics Homework Help
Replies
3
Views
1K
How do you calculate wind speed using the Doppler effect?
    • Introductory Physics Homework Help
Replies
4
Views
2K
Beats calculation/Doppler Effect
    • Introductory Physics Homework Help
Replies
1
Views
1K
Spring and Microphone (Doppler Effect...?)
    • Introductory Physics Homework Help
Replies
7
Views
2K
I Deriving Doppler Effect Frequency w/ Stationary Person & Moving Source
    • Mechanics
Replies
3
Views
706
Calculating frequencies with the Doppler Effect
    • Introductory Physics Homework Help
Replies
1
Views
2K

Hot Threads

Recent Insights

Back
Top