Fire Engine siren demonstrates the Doppler Effect
User comments:
[2012-04-20 18:42:07] timoulete76 - Sheldon bring me ...
Sheldon bring me here too
[2012-03-30 00:47:03] MRMCGALLO - just watched this ...just watched this video in physics yesterday
[2012-03-15 00:02:36] TaeHyunTJ - just watched this ...just watched this video in physics today c:
[2012-02-27 06:48:11] kvikaas - Big Bang Theory ...Big Bang Theory brought me here.
[2012-02-15 11:31:11] cissa95 - Did you film this ...Did you film this with your ass??
[2011-11-07 10:26:20] saljooghi1 - typing in 'The ...typing in 'The Doppler Effect' lead me here
[2011-11-03 20:03:02] YuTe3712 - Just watched this ...Just watched this video in my GeoPhysics class today. Everybody went "WOAH!" We watched it again.
[2011-10-20 03:34:55] melikecookie - republic poly gt ...republic poly gt no other videos to show ,so dumb
[2011-08-05 21:27:41] Spudst3r - Very good example!Very good example!
[2011-08-03 03:49:26] htden - As it approaches: ...As it approaches: Frequency observed = Frequency of Siren (velocity of air / velocity of air - velocity of truck) As it leaves: Frequency observed = Frequency of Siren (velocity of air / velocity of air + velocity of truck) So long as the truck wasn't accelerating in it's motion (velocity was constant), the frequency shift was constant (neither increasing nor decreasing). You can observe this in the video between frequency as it approaches and leaves. The switch is instantaneous. Neat
[2011-07-18 02:58:08] PumpManufacturers - nice examplenice example
[2011-06-23 17:19:35] TC53227 - GO TOUCH A BIG FAT ...GO TOUCH A BIG FAT VEINY COCK!
[2011-05-29 17:43:02] Lammedreng - Aaaahh......don't ...Aaaahh......don't we all love science?
[2011-05-03 16:45:27] 4dndf91 - that's not an ...that's not an accurate explanation either. This happens because sounds waves appear longer when our distance to the source of the sound increases. As the fire truck passes by sound waves are compressed thus giving the illusion of a higher pitch, and as it moves away the pitch decreases. it's all relativity baby
[2011-01-31 04:40:05] cowcowpingpong - Republic poly lead ...Republic poly lead me here
[2011-01-26 00:37:58] MistryWho - lol, my prof showed ...lol, my prof showed this in physics. best example ive seen
[2010-12-02 18:08:52] Crashdance22 - This also ...This also demonstrates the theory of relativity between the truck and the observer. To the driver, a certain amount of time passes in a single cycle of the siren (high followed by low). But because of time dilation, the observer holding the camera first hears a higher frequency followed by a lower one, making it appear that the siren is operating faster when approaching, and slower when evading. Bam, relativity at work in an instant.
[2010-11-25 20:08:09] psylover1991 - this is cool, never ...this is cool, never herd about doppler effect before (im not a science kid), and i like it a lot,very interesting :)
[2010-11-23 08:02:30] voicetube - Excellent, thanks ...Excellent, thanks for posting!!
[2010-11-11 05:04:25] desmodronic916 - Niii Nooo Niii ...Niii Nooo Niii NOooo Niii NOOO niii NoooOo Niii Nioouuu Nooo Nooou Noooo Noooou....
[2010-11-07 16:48:30] ImRatherTall - Cornwall FRS still ...Cornwall FRS still do, same truck too!
[2010-10-23 04:58:16] 16goarmy - why doesnt anyone ...why doesnt anyone else use those sirens anymore
[2010-10-07 21:57:55] cedarpaw23 - that's so cool!that's so cool!
[2010-09-06 00:33:56] ImRatherTall - and cornwall with ...and cornwall with thier old merc!
[2010-07-03 18:31:05] traintimmy - And North walesAnd North wales
[2010-06-18 11:46:10] alexanderbrowning - Nice ...Nice DopplerEffect.We can enjoy DopplerEffect everywhere on this planet.It's wonderful,isn't it
[2010-06-09 21:58:23] ladiestreat27 - lmfaooooolmfaooooo
[2010-04-20 18:36:36] fjanton83 - this most be the ...this most be the funniest sound in the world
[2010-03-20 21:46:35] KooKas2oo8 - Nice. Pretty old ...Nice. Pretty old firetruck you got there :p
[2010-01-02 21:06:20] fcofelixx - nice examplenice example
[2009-07-17 10:51:39] phenomanam - just a bog standard ...just a bog standard two tone aire horn
[2009-06-27 22:32:22] jamiehn123 - And Devon and ...And Devon and Cornwall FB do to, theres one in falmouth, on an old merc!
[2009-05-14 03:39:54] Asphalion80 - klaxons?klaxons?