Deriving the doppler shift equation for sound

Click For Summary
SUMMARY

The discussion focuses on the derivation of the Doppler shift equation specifically for sound, highlighting key differences from light. It is established that when the observer moves while the source remains stationary, the wavelength remains constant, but the observed frequency changes. Conversely, if the source moves and the observer does not, the wavelength changes while the speed of sound relative to the observer remains constant. The conversation emphasizes that both the speed of sound and the observer's motion significantly influence the observed frequency and wavelength.

PREREQUISITES
  • Understanding of the Doppler effect
  • Basic knowledge of wave properties (wavelength, frequency)
  • Familiarity with sound wave propagation
  • Concept of relative motion in physics
NEXT STEPS
  • Study the mathematical derivation of the Doppler shift equation for sound
  • Explore the differences between the Doppler effect for sound and light
  • Investigate the impact of observer and source motion on wave properties
  • Learn about applications of the Doppler effect in real-world scenarios, such as radar and astronomy
USEFUL FOR

Students of physics, educators teaching wave mechanics, and professionals in acoustics or audio engineering will benefit from this discussion on the Doppler effect for sound.

21joanna12
Messages
126
Reaction score
2
I am looking at derivations of the Doppler effect for sound and light, and I am very confused about what stays the same when it comes to sound.

In this video, at 5:10, it is said that the wavelength will be the same.

I'm not sure I agree with this because I'm pretty sure both the observed frequency and observed wavelength change, but on the other hand perhaps the wavelength would stay the same and it would be the observed frequency and velocity that would change, because I know that the Doppler shift equations for light and sound are different, and perhaps that is because all observers measure the speed of light to be the same but they measure different speeds for sound?

Then in this video, the equations on the board suggest that the speed of sound will be absorbed to be the same.


Could this discrepancy also have something to do with the fact that the first deals with a moving observer and the second deals with a moving source?

Thank you in advance :)
 
Physics news on Phys.org
Wavelength stays the same if the observer is moving, but the source does not (then the speed relative to the observer changes). If the source moves but the observer does not, the wavelength changes but the speed relative to the observer stays the same. If both move, you get both effects together.
 
  • Like
Likes   Reactions: 21joanna12

Similar threads

Undergrad Deriving Doppler Effect Frequency w/ Stationary Person & Moving Source
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Sound Wave Doppler effect question
  • · Replies 13 ·
Replies
13
Views
3K
Undergrad Find period of circular-orbiting source based on max observed freq
  • · Replies 1 ·
Replies
1
Views
2K
High School Why is the constant speed of light so unique?
  • · Replies 19 ·
Replies
19
Views
1K
Graduate Doppler shift and change in intensity of a sound wave
  • · Replies 1 ·
Replies
1
Views
3K
Graduate Doppler effect with moving medium but no relative motion
  • · Replies 10 ·
Replies
10
Views
4K
Undergrad Sound Doppler shift asymmetry confusion
  • · Replies 23 ·
Replies
23
Views
5K
Speed of moth related to Doppler Effect
  • · Replies 8 ·
Replies
8
Views
936
Undergrad Phase Speed of Wave in non-relativistic Doppler Shift Derivation
  • · Replies 1 ·
Replies
1
Views
1K
Aberration and Doppler shift in Special Relativity
  • · Replies 7 ·
Replies
7
Views
2K