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# Basic Physics III Lecture 8

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#### Automatisierte Medienanalyse

Beta
Erkannte Entitäten
Sprachtranskript
Delay may remember be phenomenon of interference of believes in general and like any other way of on rates are also in the field for example if have to loudspeakers
Maria solemn speed A frequency Time wavelength which is 1 of the period Times Thinks so it multiplied by a teacher or will beat them to get TV also lumber over reader of Now
Add this expression at end of this expression and time period In this formula we get that amount of prying the changed wavelength is not minus a land and resource velocity divided by the And you can quote me labeling Slumdog expression of that Lambert prime equal slammed the times 1 minus She source of However we also know that We have the frequency that is associated with the hourly length Must be the sound speed divided by wavelength of substitute this winter That way she wouldn't be get that These changed frequency Prime equals about on speed divided by Expression frequency Prime equals the frequency divided by the fact the one-liners A source of a and indeed If Therefore primaries They don't Since the the denominator Eckert smaller than more you increase similarly Derive on expression and we are moving away from the And in that case at Lambeau primed longer abide by this amount So Basically replaces minus sign which comes from that minus signed by a plus sign And so in that Prime equals at 4 1 plus in that Case and a This frequencies And the denominator get bigger So Unfortunately professor cast but doesn't have a program for this Case but I've found 1 on the Web so if a tire pressure has led an improbable victory despite cage and runs this job the way we can have played with the Doppler effect as far part of moving resources so right now the source is moving at all so Brandeis as circulates going in all directions but the can now start will move the source
With higher and higher velocity and now you see that And wavelength in the direction of motion becomes a smaller part of the wave away from the direction of motion and perpendicular It the direction of motion and it is about the same I want it for Look And so it is now imagine standing here in this being the fire from of bigger frequency Pressed for a 2nd then as the truck process to buy you hear this The normal frequency of sirens and ran out the year truck Passed through The year frequency and walk across a few oppressed so the next question and we ask ourselves is what happens is not the sources moving but listen so let's say dealers sitting in a car on yourself and your listening to Osama from sounded stationed there what happens in that case what happens in that
Cases that the wavelength of the same because sources will but media the apparent some pilosity Increased if you moving toward the source of the The pool velocities add so we changed a song velocity Prime Minister some more normal songs plus the emotional list And that If you try wrapped in Chualar you expression relating frequency wavering then they get that these had changed frequency It's a times 1 plus The velocity Listen over the last and in this Place Uh at Prime is also bigger than because novice Expressionist and no more and normal rate getting bigger and bigger And I assume only if we move away from the source The year to varsity track and we get this expression These Who expressions are different than what we got from the EU moving source even if you change the sign of the velocity what we have here is that It matters The EU moved toward us soloists or other source is moving toward you always moving away from the Moving away from you So in other words This is manifestly and nonrelativistic Effect meaning that it doesn't just a matter of what the relative velocity of you with respect to source But it also matters how fast moving again Media which in this case the So what happens if we both the stores and listen And become combined have both fallen all 4 formed into 1 of the changed frequencies at times 1 plus or minus a listener sound Divided by 1 minus 0 plus a source in the last 4 for the listener means that the listener moves toward the source the minors for a listener that way and for this source That just means that the 1st move toward the Minus move away from you basically just have to remove this 1 formula can keep those I Signs straight So was There's a 3rd option and
Is Neither of us modest The ruling the medium has so far we have always consider that Is still virtually which transports the sound if there's some last somewhere in there and that there's also a Doppler effect and weekend You will need a principle of relativity issue the that's physics must be ruined rebellion over absolute motion not and so we can replace the ruling medium with a moving source of will list for example let's say their source and listen still but there's a
And There is A constructive interference of a lot of ways press just this at the boundaries of what goes all the way out of the compound constructive and that means that right there it's allowed this is our usually error would refer a sonic boom so we calculate that the area the object is addressed to get circular Ashley crisis surrounding it wavelength doesn't change in any of the directions based on bullying and way get shorter and shorter in the direction of motion if at the sound speed and all be away from me just in front of the object and we go past that speed and there is a conical region sound the and Since this constructive interference of all those with protests here However high intensity just at this and there's also called a shark So and this comes about because song can't keep up with the emotional the the object we can actually so-called Mach number after the physicist much of which is B a ratio of The object be divided by the songs A plane will win with Mark No. 2 meters twice as fast And this much numbers related to The opening angle of the home opening angle means half the angle of the conical shape and sign of This opening angle be object or sound and therefore it It should be a sample of the object and therefore services Related inversely related the mark typical example All of such A supersonic booms Is it The crack of gunshot that's not to be confused Explosive really sort of gasses from from the gun which you can watch a shield of dampened with but the actual shot sulfur was snapped or crack and vectors Such a shock Produced by supersonic with a more familiar example perhaps supersonic jet fighter In this case as multiple shock waves basically every part of the plane Producing such a shock wave and in this Picture The shock waves are made visible and you see for example the shock wave of knows he has also won produced here and in general can distinguish those that are produced by the front of the plane and blow with up in detail but the reality is more complicated than just to shop or we can look at what awaits and a speed boat And then there are the same phenomenon happens the speed voted for it goes faster passes all of it Crest of its own weight and And that produces a shock wave that sort of wolves in somewhat comical shaved away from in the case of the jet Elaine Panasonic will not be a shock waves and worry intends can cause considerable damage for for example it can win Let me finish today of the various applications of found the first one that comes to mind are must detect underwater objects by using the time delay often echoing song in the sonar you a amid solemn pulse and then you wait for the reflection coming back 2 and a judge from the reflection of what kind of objects on you Or out tentatively with the same principle 1 appropriate Connell structural growth and using Braves traveling tho would be often these swathe of produced intentionally The explosion but I can also use earthquake waves that happened and naturally To maximize and the case of sold last 1 usually uses ultrasound waves and Bettis Because of a Wavelength shorter and therefore we Diffraction effects plus more It's a kind of was also used in medical imaging so-called sonogram images used for for diagnostic purposes and so it uses the the same principle as the St. Paul's echo technique so now typically frequencies used up between 1 and 10 megahertz
And echoes are observed from any kind of boundary in the body will be density changes for sample of organs Lesions or Cuomo's through fluid pockets or anything else In that case you have friends friends to so Place outside human and then married produces sounded reflects all of those areas Ingredients that you have in the human body and for each 1 of them receive an echo then that you repeat this procedure by replacing the funds to set of slightly different positions like this
Picture here and so if you make many such places to you observe different kind of Eccles and you can form a kind of image of what has happened Aside from Blair but you need to know of causes the the sound velocity body which Roughly the same as that of water or 1540 meters at the time delay between admitting the pulse and observing that related to distance The boundary twice the last Time and be intensity of The echo tells us something about the difference in density of the various media The most famous example probably will look Pictures A human or human fetus for example of 1 and 1 can see that it's possible to make a detailed picture and we can then make use of the Doppler effect to check whether that's a hot lead off our its used in them for other diagnostic purposes could detect The emotional bloodstream So let me know summarized Chapter 16 so 1st of all sound means But with Sensational consciousness about Physical phenomena that originates that has sound lays on along botulinal waves which means that air molecules for example vibrate Along the Directions propagation Saunders transported in a or other materials The sensation of pitch Is related to the frequency human beings can heal frequencies Between tainted goods and a 20 thousand The sensation of loudness is related to the intensity and the way we perceive loudness is proportional the Barber with intensity or I read can define the sound level has 10 dB times The Barber of all the intensity I divided by The intensity I'm not I'm not is taken As the human hearing special What 10 to the minus 12 walks the square The sources of sound of vibrating objects and typically standing waves of the Jews and those by ripping on a frequency All of the solemn in a L and is the same as the frequency of the vibrating object but the wavelength is typically different if the vibrating object is a string off some length or if it's an open air column in the tube that is open on both sides that the fundamental a wavelength the fundamental mode is given by twice the length and then odd and even higher harmonics exist and foreclosed to which means that 1 end disclosed the other 1 is open the fundamental wavelength its 4 times length and only odd harmonics Exerts a wave length off the end harmonica Given by a fundamental wavelength divided by And the frequency Given by fundamental frequency multiply and finally ended Doppler effect changes picture of sound or the frequency If the source or other listeners are moving using this formula is media moves 1 can replace that motion with the appropriate motion source and list objects moving faster than the on velocity Amid shock waves called sonic booms and saunas and medical in Ching devices use ultrasound echoes to determine that distances to objects
Thank you very much
Schaft <Waffe>
Elektrisches Signal
Mikrowellentechnik
Gelenk <Technik>
Summer
Sonnenstrahlung
Festkörper
Konfektionsgröße
Tonfrequenz
Interferenz <Physik>
Kaliber <Walzwerk>
Chirp
Briefumschlag
Satz <Drucktechnik>
Nanometerbereich
Leistungssteuerung
Leitungstheorie
Bügeleisen
Trenntechnik
Montag
Fahrgeschwindigkeit
Lautsprecher
Speckle-Interferometrie
Amplitude
Feinschneiden
Multiplizität
Interferenzerscheinung
Schall
Verpackung
Wellenlänge
Kaltumformen
Längenmessung
Übungsmunition
Werkzeug
Negativer Widerstand
Stuhl
Flüssiger Brennstoff
Mikrowelle
Jahr
Lineal
Ersatzteil
Interferenzerscheinung
Ersatzteil
Brillouin-Zone
Interstellares Gas
Stringtheorie
Tonfrequenz
Feuerwehrfahrzeug
Kaliber <Walzwerk>
Chirp
Briefumschlag
Druckmaschine
Juni
Umlaufzeit
Biegen
Elementarteilchenphysik
Randspannung
Klangeffekt
Schall
Wellenlänge
Längenmessung
Crestfaktor
Messgerät
Doppler-Verschiebung
Übungsmunition
Source <Elektronik>
Elektrogitarre
Source <Elektronik>
Mikrowelle
Ersatzteil
Fliegen
Goldschmiedehandwerk
Kraftfahrzeughandwerk
Kraftfahrzeugexport
Sirene
Tonfrequenz
Kaliber <Walzwerk>
Platzierung <Mikroelektronik>
Umlaufzeit
Prozessleittechnik
Gießen <Urformen>
Fahrgeschwindigkeit
Elementarteilchenphysik
Winter
Wellenlänge
Zirkulator
Intelligenter Zähler
Luftdruck <Reifen>
Minute
Übungsmunition
Doppler-Verschiebung
Source <Elektronik>
Schiffsrumpf
Gleichstrom
Lastkraftwagen
Source <Elektronik>
Mikrowelle
Jahr
Ersatzteil
Unterschallgeschwindigkeit
Schall
Wellenlänge
Relativistische Mechanik
Interstellares Gas
Tonfrequenz
Chirp
Doppler-Verschiebung
Wasserbeckenreaktor
Übungsmunition
Gleiskette
Elektronische Medien
Source <Elektronik>
Source <Elektronik>
Jahr
Lineal
Fahrgeschwindigkeit
Direkte Messung
Interstellares Gas
Klangeffekt
Wärmeaustauscher
Atomphysiker
Motorjacht
Gagat
Hammer
Fehlprägung
Kaliber <Walzwerk>
Schallmauer
Prozessleittechnik
Kristallgitter
Passfeder
Fahrgeschwindigkeit
Stromschlag
Multiplizität
Array
Wellenlänge
Kaltumformen
Crestfaktor
Stoßdämpfer
Übungsmunition
Doppler-Verschiebung
Schallmauer
Reflexionskoeffizient
Intensitätsverteilung
Direkte Messung
Kampfflugzeug
Interstellares Gas
Anstellwinkel
Stoßwelle
Kraftfahrzeugexport
Sensor
Sirene
Tonfrequenz
Fahrgeschwindigkeit
Hitzeschild
Hobel
Chirp
Förderleistung
Nanometerbereich
Druckmaschine
Schall
Beugungsfigur
Sonar
Kopfstütze
Elementarteilchenphysik
Speckle-Interferometrie
Chandrasekhar-Grenze
Klangeffekt
Interferenzerscheinung
Schall
Schusswaffe
Front <Meteorologie>
Behälter
Schonerbrigg
Gas
Source <Elektronik>
Gleichstrom
Mikrowelle
Source <Elektronik>
Sprechfunkgerät
Ersatzteil
Unterschallgeschwindigkeit
Stoßwelle
Bleisatz
Stringtheorie
Tonfrequenz
Leisten
Kaliber <Walzwerk>
Krätze <Metallurgie>
Nanometerbereich
Be-Stern
Feldeffekttransistor
Echo <Ballonsatellit>
Oberschwingung
Fahrgeschwindigkeit
Elementarteilchenphysik
Speckle-Interferometrie
Schalldruck
Schall
Wellenlänge
Gasdichte
Längenmessung
Elektronische Medien
Doppler-Verschiebung
Übungsmunition
Schallmauer
Nassdampfturbine
Grundfrequenz
Gleichstrom
Atmosphäre
Source <Elektronik>
Mikrowelle
Intensitätsverteilung
Material
Tonhöhe
Unterschallgeschwindigkeit