Speed of sound Definition and 271 Threads

The speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elastic medium. At 20 °C (68 °F), the speed of sound in air is about 343 metres per second (1,235 km/h; 1,125 ft/s; 767 mph; 667 kn), or a kilometre in 2.9 s or a mile in 4.7 s. It depends strongly on temperature as well as the medium through which a sound wave is propagating. At 0°C/32°F, the speed-of-sound is 1192 km/h, 741 mph.The speed of sound in an ideal gas depends only on its temperature and composition. The speed has a weak dependence on frequency and pressure in ordinary air, deviating slightly from ideal behavior.
In colloquial speech, speed of sound refers to the speed of sound waves in air. However, the speed of sound varies from substance to substance: typically, sound travels most slowly in gases, faster in liquids, and fastest in solids. For example, while sound travels at 343 m/s in air, it travels at 1,481 m/s in water (almost 4.3 times faster) and at 5,120 m/s in iron (almost 15 times faster). In an exceptionally stiff material such as diamond, sound travels at 12,000 metres per second (39,000 ft/s),— about 35 times its speed in air and about the fastest it can travel under normal conditions.
Sound waves in solids are composed of compression waves (just as in gases and liquids), and a different type of sound wave called a shear wave, which occurs only in solids. Shear waves in solids usually travel at different speeds, as exhibited in seismology. The speed of compression waves in solids is determined by the medium's compressibility, shear modulus and density. The speed of shear waves is determined only by the solid material's shear modulus and density.
In fluid dynamics, the speed of sound in a fluid medium (gas or liquid) is used as a relative measure for the speed of an object moving through the medium. The ratio of the speed of an object to the speed of sound in the fluid is called the object's Mach number. Objects moving at speeds greater than Mach1 are said to be traveling at supersonic speeds.

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  1. Thom_Silva

    Sound source moving at the speed of sound

    Hi, Suppose that a plane that is traveling at the speed of sound has a loudspeaker attached to it. Along the he trip the loudspeaker releases specific sounds. What does the pilot ear when the first sound is released? And after the second sound is released, does he ear both sounds at the same...
  2. G

    What is the Uncertainty of Human Hearing Frequency?

    what can be the uncertainty of the frequency that humans can hear ? I'm aware that there are many ways,but i tried google-ing to find them but i couldnt. if you could help me it would be great.
  3. F

    Derivation of the speed of sound waves equation

    I'm learning about the speed of sound waves through a medium. The derivation is initiated through Impulse=change in linear momentum (I=Δp), then I=ΣFΔt=(Area×Δpressure×Δt) in the x direction The derivation proceeds by replacing the Δpressure with another equation we had derived earlier...
  4. P

    What is the speed of sound and time period of oscillating particles?

    I have a question to solve - A boy heard a sound of frequency 100 Hz at a distance of 500 m from the source of sound. What is the speed of sound? What is the time period of oscillating particles of the medium? I have approached the below way : We know that speed = distance / time...
  5. A

    What is the speed of sound in a rigid body?

    Homework Statement What will be the speed of sound in a perfectly rigid body? Given : In a hypothetical situation we have a rigid body find the speed of sound when it passes through the material. Elasticity of medium = ∞ Homework Equations velocity = √E/ρ ρ = density E = elasticity of medium...
  6. Sace Ver

    What is the speed of sound in air at atmospherical conditions?

    Homework Statement A student stands 86m from the foot of a cliff, claps her hands, and hears the echo 0.50s later. Calculate speed of sound in air. Known •86m •0.50s Homework Equations V=331.4+0.606T The Attempt at a Solution V=d/t V=86m/0.50s V=172m/s Is that the first step to the problem...
  7. G

    Fastest Terrestrial Sound Conduction Speed

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  8. H

    Depth of a well (using speed of sound)

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  9. D

    How does a whip break speed of sound?

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  10. iForget

    Time Dilation for Slower Objects - Physics Explained

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  11. J

    Calculating Speed of Sound in Nickel using Atomic Properties

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  12. E

    Speed of bowling ball involving speed of sound

    Homework Statement A bowling ball traveling with a constant speed hits the pins at the end of a bowling lane 16.5 m long. The bowler hears the sound of the ball hitting pins 2.5 s after ball is released from his hands. What is the speed of ball, assuming speed of sound is 340 m/s? Homework...
  13. Y

    Need help with physics experiment (Speed of sound)

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  14. 8eou8elisi

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  15. B

    Calculating Distance to a Wall Using Speed of Sound

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  16. S

    What is the speed of sound in oxygen? 21.50mastering physics

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  17. C

    Speed of Sound and its relation to weight?

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  18. PavanKumar

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  19. Stephanus

    Speed of Sound in Different Mediums

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  20. M

    Speed of sound and light through different solutions

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  21. S

    How far did the parachutist fall before hitting the water?

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  22. S

    How Can the Speed of Sound Help Determine Room Temperature?

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  23. D

    Speed of light vs speed of sound

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  24. P

    Doppler Effect and the speed of sound

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  25. Rumo

    Speed of sound in an isentropic ideal gas

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  26. Cluemore

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  27. AdityaDev

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  28. Ignis Radiis

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  29. 2

    Deriving the doppler shift equation for sound

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  30. Z

    Speed of sound in turbulent air?

    If I turn on a standing fan in my room how does the speed of sound change in the fast moving air compared to the still air around it? Would it be relatively faster, slower, or does it depend on the direction in which the fan is blowing?
  31. F

    Determining the speed of sound in air

    Hello! I have a problem with determining speed of sound basing on a data from laboratory. 1. Homework Statement I have to determine speed of sound by measuring the shift of time in microphone compared to speaker. The distance between them is constant and I'm changing the frequency in...
  32. Paulene Gueco

    Speed of Sound in Air as a Function of Temperature

    Hi, guys! :) I do hope I am posting on the right thread here. So anyways, I'm looking into a certain topic: "Speed of Sound in Air as a Function of Temperature". Any thoughts on how I could do this experimentally? Warm regards, Paulene :)
  33. G

    Does the speed of sound depend on the observer's relative motion?

    Hi, I wanted to ask if the speed of a sound wave, given a fixed medium, depends on the speed of the observer. That is to say, does the speed of sound obey to the laws of relative motion, implying addition of relative speeds? In case it doesn't depend on relative motion, can you explain why? I...
  34. H

    How does density affect the speed of sound?

    So the speed of sound is dependent upon two properties: 1) Elasticity of the Medium 2) Density of the Medium. Greater elasticity results in a greater restoring force once the molecules are displaced (similar to a spring) so they return to their original positions sooner meaning they can...
  35. C

    How Does the Doppler Effect Help Determine the Speed of Sound?

    Homework Statement Problem: a car is moving away from a stationary observer at 25ms^-1. It emits a frequency of 810Hz and the observer hears an apparent frequency of 762Hz. What is the speed of sound in air at that time? Homework Equations The equation for a source moving away is f' =...
  36. A

    The Speed of Sound: Changing with Medium

    Hi all. How does the speed of sound change with the medium? That is, how does it change with density, molar mass, temperature and in air, humidity. It seems that denser materials would increase the speed of sound, since the particles are more closely packed and therefore ease vibrations. The...
  37. T

    Height of cliff using energy and speed of sound

    Homework Statement [/B] A stone is dropped from the top of a cliff. The splash it makes when striking the water below is heard 4.0s later. how high is the cliff Homework Equations .5mv^2+mgy = E v = v0 + at v = d/t The Attempt at a Solution The question says after the rock is DROPPED so i...
  38. C

    Resonant Frequency and speed of sound

    1. Hollow tube chimes are made of metal and are open at each end. One chime is 0.54m long. -If the speed of sound is 346m/s, what is the frequency of sound produced by the third resonant length? -What would happen to the frequency of sound produced by the third resonant length if the chime...
  39. R

    What Does an Observer Hear When Traveling at the Speed of Sound?

    Hi everyone, A couple of question I was thinking about regarding sound: 1) A sound source is moving at the speed of sound, and because sound waves cannot move faster, the waves build up at the front (direction of movement). If there is also an observer at the source (traveling at the speed...
  40. GerryB

    C as the speed of light and the speed of sound in Michelson-Morley.

    The symbol, c, represents both the speed of light and the speed of sound in most scientific reference texts. Can the speed of sound be substituted for the speed of light in the Michelson-Morley (MM) formula: T = [L / (c - v)] + [L / (c + v)]? Consider an observer on a train of length, L. It...
  41. paulmdrdo1

    MHB Speed of sound - Uniform motion- linear equation application

    I need help with these problems. 1. Speed of Sound in Air. Two seconds after firing a rifle at a target, the shooter hears the impact of the bullet. Sound travels at 1100 feet per second and the bullet at 1865 feet per second. Determine the distance to the target (to the nearest foot). 2...
  42. Adithyan

    Speed of sound on a moving train

    Homework Statement Two trains A and B are moving with speed 20m/s and 30m/s respectively in the same direction on the same straight track with B ahead of A. The engines are at the front ends. The engine of trains A blows a long whistle. Assume that the speed of sound of whistle is...
  43. Manraj singh

    Speed of sound waves in various media.

    My tenth grade physics textbook says that sound travels faster in solids than air. But it also says sound will travel faster in air if its density decreases. I didn't really get the logic, as solids are denser than air, and that is why sound travels faster. Then they say as temperature of air...
  44. P

    The police car moves faster than the speed of sound? Sonic boom.

    Hi, Suppose the police car moves faster than sound's speed and runs away from the person on the street. Will the person hear the siren? Regards,
  45. P

    The police car moves faster than the speed of sound?

    Hi, Suppose the police car moves faster than sound's speed and runs away from the person on the street. Will the person hear the siren? Regards,
  46. N

    Understanding the Speed of Sound in Fluids: An Explanation from Thermodynamics

    Hi The speed of sound in a fluid is defined as c_s^2 = \frac{\partial P}{\partial \rho} where P is the pressure and ρ the density. In my thermodynamics-course this was how we defined the speed of sound in an ideal gas, I have never read the explanation anywhere for, why this relation is also...
  47. S

    Determine depth of a well using the speed of sound

    Homework Statement If you drop a stone into a deep well and hear a splash 4.68s after dropping the stone, how far down is the water level? Neglect air resistance and assume that the speed of the sound in air is 3.40x10^2 m/s Homework Equations v=d/t d=v1t+1/2at^2 The Attempt at a Solution Here...
  48. G

    Speed of sound wave and particle velocity

    This may be fairly straightforward but it is a concept that I am really having problems understanding. A sound wave is a pressure disturbance that travels through a medium by means of particle to particle interaction, so why is the wave velocity so much faster than the velocity of the particles...
  49. B

    Please help Speed of sound in air/temperature relation

    Homework Statement The density of a sample of air is 1.211 kg/m3, and the bulk modulus is 1.42 · 105 N/m2. a) Find the speed of sound in the air sample. b)Find the temperature of the air sample. Give answer in °C. Homework Equations The Attempt at a Solution I found...
  50. B

    Rock off cliff - calculate height by using speed of sound

    You are climbing in the High Sierra where you suddenly find yourself at the edge of a fog-shrouded cliff. To find the height of this cliff, you drop a rock from the top and 8.50s later hear the sound of it hitting the ground at the foot of the cliff. Ignoring air resistance, how high is the...
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