Sound waves and gravity question

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Discussion Overview

The discussion centers on the relationship between sound waves and gravity, specifically whether sound waves are affected by gravity and if they can have varying velocities. Participants explore the nature of sound waves in different media and the implications of gravity on their propagation.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Homework-related

Main Points Raised

  • Some participants assert that sound waves are not affected by gravity in the sense of being "bent" because they lack mass and concentrated energy.
  • Others propose that the speed of sound is influenced by the properties of the medium, such as density, elasticity, and temperature, rather than gravity itself.
  • A participant suggests that if sound waves are affected by gravity, it would be through its impact on the medium rather than the sound waves directly.
  • One participant questions whether neglecting air resistance means sound would have a constant velocity and not require consideration of acceleration.
  • Another participant emphasizes that sound requires a medium to travel and cannot exist without it, indicating that sound cannot travel in a vacuum.
  • A later reply introduces the idea of waves in the upper atmosphere that are influenced by gravity, mentioning 'rippled clouds' and the concept of 'Atmosphärische Schwerewellen', suggesting a different context for wave behavior under gravity.

Areas of Agreement / Disagreement

Participants express differing views on the influence of gravity on sound waves, with no consensus reached on whether sound waves can be affected by gravity or how their velocities should be treated in various scenarios.

Contextual Notes

Some discussions involve assumptions about the medium and conditions under which sound travels, as well as the definitions of sound waves and gravity's role in wave propagation.

kay2500
[SOLVED] Sound waves and gravity question

Just a small question: are sound waves affected by gravity, and can thye have an initial and final velocity, or do they always have a constant velocity and do not need to accelerate?
 
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Sound waves are compression waves in the atmosphere (or water, metal, etc. if they are moving through those).

Since they have neither mass nor the concentrated energy of light, they are not affected by gravity in the sense of being "bent" by gravity.

The speed of a sound wave is dependent on the "natural frequency" of the medium and so is affected by such things as air density. It is possible for sound to "reflect" or "diffract" when moving from an air mass of one density to another.
 
Sound waves are inside movement of medium. If sound waves are affected by gravity, it would come from the effect of gravity on the medium. Speed and acceleration of sound waves are to come from property of the medium such as elasticity, temperature, anisotropy, existence of defects, etc.
 
Hmm, so if I'm neglecting air resistance, then I don't have to worry about the sound "reflecting" or "diffracting"?

I suppose I should explain the problem that I'm deriving this question from ^^;;

Basically, it asks you how far sound has traveled in 3.4 seconds if there is no air resistance. So I'm assuming, by your replies, that with no air in the way, sound would have a constant velocity and I wouldn't need to factor in its acceleration?

Sorry if this all seems rudimentary to you, I'm starting AP Physics the coming school year, so I'm only going over pretty much the basics =P
 
No air, no sound, isn't it. Sound we hear is usually a vibration of air.
 
Well, I never said these problems made sense :P
 
Air resistance doesn't apply to sound waves. Its not like a plane. Sound needs a medium to travel through. Without air (or other medium) there can be no sound. True, sound loses energy as it vibrates through the air, but that can't be considered air resistance in the most familiar sense of the word. If you negelect that, the sound wave will travel forever, unless it hits something else, that is.
 
... unless it hits something else ...
Or maybe leave the medium to space too ?
 
Actually, there are waves in the upper atmosphere which are largely governed by gravity. Have you ever observed 'rippled clouds'? Well, I think these are created by 'orographic motion' in the atmosphere, where the gravitational component gets in the same order of magnitude as adiabatic pressure & density. I learned this under the German term of 'Atmosphärische Schwerewellen'. Well I guess you can't really call this 'sound'. But you get the solution from the same wave equation, if you *don't* neglect gravity.
 

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