Speed of Sound | Mechanical waves and sound | Physics | Khan Academy

How fast does sound actually travel? Created by David SantoPietro.

Physics on Khan Academy: Physics is the study of the basic principles that govern the physical world around us. We'll start by looking at motion itself. Then, we'll learn about forces, momentum, energy, and other concepts in lots of different physical situations. To get the most out of physics, you'll need a solid understanding of algebra and a basic understanding of trigonometry.

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[gsky]

I think this is better than a book explanation -- took less than 4 min --
thanks to who ever put the time and effort in to this explanation is much appreciated

[MichaelCarrPilot]

Three Minutes and Fourty-four seconds of pure educational content.

Finally, an educational video that doesn't have extra BS!

Bravo!

[WSCOMPUTER]

This is another fantastic "sound" video! I've never seen such clear and thorough presentation of waves. Keep recording such videos in this manner.

[turboroscoemaguedavedicker]

The speed of sound ... while living in North Alabama ... I watched as jet fighters flew past quietly at over 800 MPH. A moment of silence

[crashsitetube]

@3:13 he says that "People often think that changing the amplitude will change the speed of sound...." Of course people also often think sound is longitudinal compression waves and that air molecules are moving back and forth to make those waves.

Notice that, in his animation, the molecules are being 'pushed' and 'pulled' by the loudspeaker. It's pretty easy to visualize why the air molecules would be 'pushed' but, what forces on the molecules 'pull' them back toward the speaker?

the usual way to resolve this question is to refuse to acknowledge that it's been asked.

What happens if the speaker constantly moves in the 'outward' direction (as it would if it's mounted to the front of a truck zipping down the highway, even if there's no electrical signal being fed to it)? Does the speaker continually push the air molecules forward? If you are 100 meters in front of the speaker (and thus the entire front surface of the truck) push out a 'crush' of air that you can feel strongly?

That's an easy one to test. Stand along side a highway (safely) and notice if you feel a compression of the air against your body each time a car or truck approaches. Hint: You feel nothing until the vehicle actually passes by.

Oh, wait. Never mind. This is another one of those questions that physicists must never ask or acknowledge has been asked.

[AKB]

Guys, You're videos put the concepts directly into the grey matter ( whatever part which is used for storing / understanding things ) of my brain. Even I can get the concept at the first shot . Thank You so much . You're doing a wonderful meaningful job. Thanks again.

[anikarichie]

One of the best explanations so far I must say.

[estradadamien]

Thanks for all who allowed me to get my ideas out there I know I have no voice but I'll do wat ever too make sure they will always be heard

[loroycf]

YOU! Really!
I had been studying light and sound refraction (for fiction writing purposes) and I knew the longer the wavelenght in light, the more drastic the refraction would be. I wanted to know if this was the same with sound (as you see I'm no expert in physics) but since this is not the case and it is obvious for a scientist, I hadn't found an answer to my question so far. You didn't only give me a "yes" or a "no", but you helped me understand.
Thank you for answering even the obvious questions that "nobody" asked, this is the way to go. (Liked and subscribed, even though I've had the Khan Academy app for some time now)

[methasawijayasuriya]

Super explanation.U people always clear all the doubts I have.

[palak]

No other video has explained the concept that it has right entered the 💓

[prabodhgaikwad]

Very helpful!! Well explained!! Thanks a lot!

[johnbenedictflorendo]

nice its true to convert it to electric wave=weight in motion

[anilkumarsharma]

how to check out the density or measures the size of pipe by sound waves based meters

[shivanihr]

If speed of sound is constant (344m/s) then why do we calculate speed of sound for different wavelengths, with the formula ... speed of sound = frequency x wavelength. Because there are numericals given in kid's textbook to find out speed of sound with the given frequency and wavelength. Some websites on Google says speed of sound is uniform (344 m/s) and does not depend on frequency or wavelength, when the opposite is clearly given in the formula. Please explain.

[uroobanoor]

Good to see such video from my own country 🌹🇵🇰🌹❤️❤️❤️

[anilkumarsharma]

is their any meter of such types which calculated the size of pipe, it's outside diameter and inside diameter and density per cubic inches or centimetres

[Hino_]

Great explanation sir David, thanks :)

[stressedoutkid]

I've my phy alevel exam literally 1 day away.I need prayers bois i haven't prepared much

[feliwx]

Why are all sound graphs shown in a transverse wave whereas sound waves are longitudinal waves