Doppler effect formula for observed frequency | Physics | Khan Academy
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Published 2010-06-05
Let's derive the formula for how the perceived frequency of a sound changes when its source is moving toward you. Created by Sal Khan.
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All Comments (21)
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Helped me get through mechanical waves, not just this video obviously! Thanks a lot!
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muchas gracias Sr. Sal. Esta es la conferencia más detallada e inclusiva a la que he asistido sobre este tema ...
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Perfect! Thanks a million
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The time period measured by the observer is the time taken between the first crest and second crest to reach the observer .. thanks, its an awsum derivation.
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i'm pretty sure that someone who's watching a video on Doppler's effect would have reached a level that they know that distance is velocity times time. thank you for still explaining every little thing.
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Thank you so much.. you cleared my confusions and doubts...
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Brilliant. Thanks so much!
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You saved me from my Physics Periodic Test. TNX \m/
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thank you very much. you told very understandable
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wow much better explanation than my teacher did thanks a lot
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thank u for solving my problem!!!!!!!
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great video. what software are you using to make it?
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Thank you so much :D this makes no sense in my textbook haha , but now I get it
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It's the same principle. Whether a car is moving towards you at 5 mph or you are moving towards the car at 5 mph is irrelevant, the waves act the same. So, if there is a problem where you are moving towards a stationary object at 5 mph, you can treat it as if the object is moving towards you at 5 mph as well. Or, (even though in relativity this isn't exactly the case) if you are moving towards something at 5 mph and it is moving towards you at 20 mph, you can treat it as if it's moving 25 mph
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Hey KA! I was using your iOS app to watch Doppler Effect videos, and I noticed that this video is missing from the playlist. It provides a bit of a logical gap, so it'd be helpful to update the app (and maybe even the website if it's missing from there too).
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best video on this so far
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thank you so much
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@theonlymoak, In that case it will depend on whether the police and the car being chased are in motion or not. If the car being chased moves faster than the police, then we should take the case where the source is stationary and the observer is moving, in that case, the relative frequency of the pulse emitted will increase. With this, the police will be able to find the relative position of the thief(chased car) by finding the distance.
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thank you!
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Great video!
