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Basic Physics III Lecture 13
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Title  Basic Physics III Lecture 13 
Title of Series  Basic Physics III 
Part Number  13 
Number of Parts  27 
Author 
Smy, Michael

License 
CC Attribution  ShareAlike 3.0 Unported: You are free to use, adapt and copy, distribute and transmit the work or content in adapted or unchanged form for any legal and noncommercial purpose as long as the work is attributed to the author in the manner specified by the author or licensor and the work or content is shared also in adapted form only under the conditions of this license. 
DOI  10.5446/12949 
Publisher  University of California Irvine (UCI) 
Release Date  2013 
Language  English 
Content Metadata
Subject Area  Physics 
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Transcript
00:05
for the last time Stoddard discussion of followed Carlos and respect from this slowest wavering in India just as a
00:17
reminder that color is something that happens no brain and therefore it has something to do with how all eyes on as well as With the the physics of life and have free primary colors because we receptors sensitive a different In physics meals only wavelength and frequency the color is just the robot sensational of the research so um this is year visible spectrum from 409 leaders who little bit beyond 700 we also discussed last time that a light and some medium then voluntarily between 1 medium and the other can only have 1 frequency therefore the frequency of a wave is not changed when moves across since the speed changes from seem to be aware of the wavelength has changed and that means that the wavelength in the medium of the refractive index and he has air speed in the past right which is C O M and that means the a wave length in the medium ensured our 1 and compared to that of back so let's look at an example
01:47
let's say every have object that emit 659 only light in here and we see that as a red but this is only true in you to observe the same object underwater it still looks red even tho the wavelength of all the witches lumber and it's a 650 not only 1 . 3 3 which is about 480 99 on light of that wavelength would ruin him and the question is why doesn't the light of rule and was no longer be answers said a color receptors in the united and must be sensitive to frequency rather than wavelength and since the frequency is not changed underwater lights still looks however still classified color by wavelength rather than frequencies because it is easier to measure wavelength reduced the frequency the optical frequencies also hired a boat on the order of 10 of the 14 let me now discuss
02:58
refraction on on pools surfaces and they've already gone would you example where we talked about fractions of a slap of black with the pools apparel if it would demand an angle we did a prison let's say we have tools just an glass inside and they're on the outside and now right at the time the incident great gets refracted once demanded gets refracted at the and as we know from snarls all cultural get this and will fade away from August signed fatal on equal sign incident at times the ratio and mail black and to get see other angles we look at this time this angle he has the same angle alpha that here and the reason for that because these are almost whose got lines between Miles intersect each other the same analyst your original airplanes and cases and allow this must be a complementary and my mind and so we all that that for some of these the angle so they don't want to hire miners out must be equal to Piura 180 degrees that means that some more they don't want to the tool must equal given that had this relations can express now the size of data as a sign of from fatal 1 and using 1 of the trigonometry identities getting this assigned on minus cos I'm out of signed consignee fado while we get from the snails long and for cause they don't want to use that close science Korea fatal 1 plus science Griffey on what the and the formula site they don't want to get a reservation so we have this term and we had a that chairman of course I now find cosine given calm since you know what sign faded tours Wikinews snarls not signed favorite so this is how it would treat double refraction from full services that I mangled respect let now talk about the new phenomenon what happens if logged in matters report the signing of the reflective and refractive angle is bigger than 1 Of course it is impossible for any and are a refracted it can only happen if you go from on water optically dense medium to 1 that is less than for example can go from water and air In any case whenever we have refraction we always have been in addition to the refractive Korea reflect the those 2 things croat together with this condition there's just reflects reflection and I'm going to make sure that this our water tank of tow days ago so injecting a light gray hair in the water and then it reflects on from horizontal surface and we can see the refracted parade and increase the incident angle to start to CEO reflected played down here and if I increase a little bit further than refracted Ray becomes horizontal that means that signed fado refracted equals Somalia hitting the this condition and will lose it more off than there is no longer refracted parade and the only way that is left is reflected so that angled conceded 2 years a boat 49 degrees and we can calculate that angle simply from the condition is critical and signed traders see must be the ratio of the Arab refracted through incident an index of refraction we are exactly at this critical angle then the refracted angle 90 degrees so that corresponds is point total internal reflection has as many applications but before we
08:10
go into that consider an example let's say that they have a personal inside the legal pool and look straight up at the world From beneath their perfectly smooth surface and the question is how does that look like for the answer would be index of refraction of water 1 . 3 and not only in bits of French for air which is 1 and so the ratio of those 2 was 0 . 7 5 and get signed of the critical angle at 0
08:48
. 7 5 that means that the critical angle 49 degrees just like I just showed would be a water tank so up to an angle of 49 degrees a prison full can see the outside of the pool of beyond that angle the person will see just we reflection from the ground and from the walls of the pool the late so in other words will have circled the entire outside of this projected circle and beyond this circle area just see the ground on the wall next time you go ahead you go swimming can try this out how this looks for water it's 49 degrees if you try to do the same thing member very good Scotch ahead if the index of refraction as is different and so it is the critical and of cause everything would look a little bit yellow SS said total
09:55
internal reflection has has many users said it also has a certain kind of beauty to it so the reason why I am white diamonds in high demand as jewels because the index of refraction avalanche 2 . 4 2 0 and that means that a total internal reflection happy happened already in this case the critical angle is slowest 24 degrees and that means that light is running around in the visual until it hits surface with the angle is a sufficiently small less than 24 degrees so that it can escape and that gives the diamond its sparkle and since index of refraction is large the disposal effects also so those sparkles on different color another application of more technical application of total internal reflection as there have been opulus so often want doesn't use murals 1 wants to reflect their but rather a reflection prison for binoculars you want to work in groups image you can't be the prime rate image of binoculars this inverted anyone of put it back the way usually looks and to do that with tool reflection prisons like these were better than mirrors because total internal reflection almost without loss of reflectivity use it is very close to 100 per cent and even for a superbly good can't match for that since the the reflectivity is so high that you can have as many reflections with all of them losses chant demonstrated that a little plastic jobs here and I'm going to inject light sufficiently small angles and you can see the light bouncing around from from surfacetosurface to service and coming out at the other end and that means this part acts like a light guide and even works and when bend this little that so long as the bending and list not too bad and it can actually see the light coming out the other end is becomes more parent objective and this spiral and you can see the light coming on that and off cause 1 can deliver them for various color wavelengths we can construct optical cables that are able to guide the light over long distances with about loss and that is really interesting for speed Internet connection for example with modulated light beams and privacy and you can get capacities of transmission rates of up up to 10 of the 12 % but this is
13:17
not the only application and thus may also upped occasions and medicine so they should take a bundle of optical fibers together and you get a light pipe and that can be used to transmit an image from place it's hard to get true to your camera and that such places could be for example patients lungs star Michael colon you can even light up the environment by using more optical fiber to transmit light down of course all these 5 us have to be optically insulated from each other and that is done with us encoding with and different index of refraction so the latest looks them as let's say we have ever let 8 years and the of I was there and each I will transmit the color right next to the image on the other side which we don't have let me and now talk about a refraction the circles so let's consider race starting at point old and moving up to hide H and then striking a spherical surface and getting refractive moves to point and if you wanna know all the position of I
14:50
respect function also the distance of all with respect the use smells long but he'll make approximation that angles pot Small Solar who deal with the angles again consider triangles so if the angle point
15:12
I as received from point P the light strikes In order the gamma and fate tool is the angle of fraction this on seized the scent of spherical then faded tools plus gamma plus this angle find there must be equal to 100 and sold that for faded to purchase them time minus 5 minus down and minus complementary angle what kind of records and fate of witches angle the normal physicist point sendoff or these spherical surface with respect appoint Pete now we have expressed they don't who as a function of the angle at beta just directional normal and the direction of refractive Grace down we now consider approval and angled was . and we get a similar relation tho not all our Alpha Beta the complement of the incident angle equal to 180 degrees and that leads to rule out a 1 equals about speed so now we make a small angle approximation which means that we assume that the sine function and the tandem functional from 1 angle equals that angle itself so if have and 1 they don't want that is approximately equal to end smells long for small angle favor 1 and since we know that 1 is out of that means and worn out a spate of must b about a tool times they'd tools tow times they don't mind is down which comes from this so we can now say that Al Fatah is approximately the height h divided by the distance c o and Beta equals a height H divided by a radius of curvature of the spherical socialist off and Gallo equals divided by the distance between the spherical surface a point on it so if we do that then this
17:55
equation he becomes
17:56
NY nobody'll dress and 1 alarm with approximately equal to or minors and what would be I'm just plugging those angles so let me write this again so we had and 1 0 show us and 1 articles and to all our minds and to he that leaves and 1 0 would over us and to all would be I equals 2 1 and 1 and Arsenal age left in the formula and that means that age doesn't matter so any rain that strikes a spherical surface hide the approximation well I will get refracted 2 . I and that that means isn't image of the point is vulnerable also were for concave surfaces of course context simply assign our small euro and 50 I is smaller than 0 that these images on the same side of hasn't example the
19:07
revisits example with goggles drop Ridge but you know the pool is depth 1 leader calls appeared a shallow and you can use this equation had to get answers more quickly so in this case and 1 equals 1 . lead and 2 equals 1 share of the radius of curvature it is not a spherical surface planes just large infinity and in the form of a goggles I'd point old but appeared to be a point I thought this is image of the object and the object distanced from the surface of 1 meter and if you wanna find the distance in which we use the formula get 1 would be I equals point we feed that is the difference of 1 . 3 fleeing miners 1 Swan as the difference between indices of refraction divided by infinity of this whole a term goes away and then subtracted minus 1 . 4 1 Needham is index of refraction and what divided by D O and that gives us miners 1 month briefly for me and if we that would be I get the same answers for parts the image of the goggles which appears here is virtual managers in the water because it has a negative sign on the same side as could object but so if you Harris let's
20:56
let's say we have a CEO of previous bomb and now let's make a biggest feel free to all and I can that keep making ghost fields and there's digital look worn more like a plane on that and so 1 can describe what a plane or so the spectacles as with infinite Brady Seoul at the
21:29
bet this also tool for the creation and it can described by airplane donors and the friction but you have to use infinitely courage for and for the plane at work yeah that's given because it's in what better be discussed this problem before a census of pool of water it's 1 of the and the reason why this is . 3 3 years because we
22:03
had in the form of a difference of indices of refraction and 2 minors and 1 and that 1 . 3 3 minus 1 0 . 3 let's look at a
22:16
bus somewhat more complicated example let's say have a point source of light that this placed at a distance of 25 centimeters From the center of last year the index of refraction 1 . 5 amid glacier has a radius of 10 centered and the problem is to find the location of image but be deleted as we have actually tools the 1st we consider we were a fraction of the France 1st and then after area of construct image for that witches because I want we go to the next I'm seeing for crimes of August 1st image object for the 2nd What is is the image of the image of the week and that call I will 1st go to the 1st surfaced and that an equals 1 and 2 is now 1 . 5 the radius of curvature tensor and pipe and I object distances parts minus Z tends to be right post an example sold by a radius of curvature of 10 centimeters and object to systems 25 centimeters but that's with respect to the standoff the sphere and so we have to subtract the radius Obama get the distance of the service so that 15 so now we can use the formula and 1 . 5 0 but an image distance the difference in the indices of factional versus 1 . 5 1 1 0 over 10 centimeters and members of tracked 1 15 sending the object this 1 is the index of refraction in and if we in the anomalous and get quality 1st image that the distances minus 90 sending and because this is a negative number means the source and image on the same side of the the resources he distance of about 15 centimeters with respect and images 90 sending you away from this and on the same side and that means the distance from image 1 of the 2nd surface this is 90 centimeters this is 1 meter this 1 on 1 knee finale sequences the 2nd we have to use an object's distance of 1 . 1 man needle 110 cents and then used the formula again fell 1 0 image distance because you have the index of refraction he calls Miners your . 5 the difference the index of refraction the famous he would not sign because no blast yeah we have mine is onehalf here and then act because these surfaces is concave not Convex have a minus sign for the of mine is on fire in the Oval mine is 10 centimeters and from that a subtract minus 1 . 5 below 110 and if you plug the number that numbers we get for 110 center and that means that for the image I tool the distance from the for that damages and 7 . 5 per cent and because numbers positive means that the images on the other side the 1st 1st firstline more bad where the image of Chen won over and this is 1 15 centimeters because subtract marijuana would be for the formula a N A M O D O plus an glass with DRI equals and glass minus and air Oh will a over the radios so we subtract 1 or would be object the index of refraction they are the object from this to get and glass would I'm all those equations always With the inverse with 1 0 which makes it a little bit office to handle and because of that I want to make additional remark dealing with all those apropos equations we calculate quantities like 1 8 plus or minus 1 be sometimes it is easier to just multiply Oregon nominated a beat and then you get that this is equal to a B or error divided by beat plus minus so that can be easier to calculate rather than doing this way I usually do it this way both should give the the same let me add
28:29
some RISC this chapter of the most important thing you should remember remembers that light slows down when it propagates In an EU and that is described by the index of refraction we velocities than given as the speed of light divided by means of a fraction of them full reflection and we have a lot of reflection which has reflected angle equals the incident angle for the plane on we have the world that the images always a virtual as always up right and it always has the same size as the object and that means that image distance and altered distance of the state for spherical morass of curvature of reviews after they have a focal point and focal point means the reflections from parallel raise connect with the a focal point so the focal length the distance between sofas and focal point is a the radius divide by 2 and distinguished fool cases concave and convex and concave knows we assign a positive sign for the radius and Convex most reassigned the negative sign and that is purely convention committee formless focal raise those erased it goes through the the focus our reflected apparel concentric Grace race that go through the center of these articles they reflect on themselves and sent reflect like we sent raid clarity the
30:17
concave wall a convex or concave and this is a horizontal so essential rate it is the 1 that day the sendoff tomorrow and no matter what the coaches always have a this angle it calls equals that and there's the same also for playing so added this is why not the
30:54
way to construct an image graphically you can use the apparel rays which both with a focus in the reflection than the focal raised which peril the consent to graze which reflect on themselves and the century which reflects like things and in general the mall race you lose and principal you need only to find an image but the more use the better your actress gone we can use array diagrams to construct images we can also use the right radiation which gives us the image location directly we can use the magnification equations tell us we racial of the image hype over compared to the object and this is given by a formula of this might be image distance of the object once it found the occasion of the image we also modem and their real and virtual images and then we'll images they meet we'll raise so even those regiments in itself doesn't really have a reality to it but they actually libraries coming from the point space while good full images both just continuations that make enough brain of phrase that on the other side of the convex knows only make virtual images and those images are always smaller than we just like there's a long way off a reflection this refraction and the lawyers that the refractive index times the size of the refractive angle equals index of refraction of we incident at times the size of incident and light of wavelength alumna entering the medium index of refraction and has a reduced alarm and the frequency doesn't change light frequency determines the color but still we use wavelength and a 2 describe the color of the classified and 409 leaders corresponds to violent and 759 on the crows on red the index of refraction depends on the wavelength which called dispersion and if we have over effective index that a small up for the medium where the rate goes into that total internal reflection can happen if the angle is bigger than the critical angle this expression at the very end I wanna just introduction in the next chapter of which will discuss lenses in particular and optical instruments or on this picture for example lenses contact lens the cornea of the human the lens or on just standard microscope and this is 1 of the best optical telescopes the monarchy and so what is the lens lens is a conjunction of tools spherical so we have just like we discussed before we have across this here but now instead of just the blast continuing have a 2nd boundary with different radius of curvature and principle and so now we can now just like with these examples U.S. spherical last weekend struck the final image by 1st constructing image in all that and there would be object class and glass of wine equals the difference between and last month what or what and you know that miners and glass over would you 1 but he want is the 1st image plus a mail equals a mail miners and blast divided by miners saliva signs for Otto is because the surface cross the other away for minus there and a reason for the minus sign here that is rich with respect for the 2nd services on the other side for the Apple Store equations then the and glass awarding wonders I can't just left with an airworthy object class and there would be image equals the difference of indices of refraction times 1 0 or 1 plus 1 or 2 and if we divide Biennale this looks exactly like a creation will be 1 over the frequency of its given by this expression and that means that the image of such a system will behave exactly like a like a memorable and I'm going to shoulder Steel Creek and assimilation well you have a lens you bitch with some focal length and for example we can headed the beam and 28 with a beam of apparel light it gets focused and the focus into 1 . 2 till mangled then it goes into a different point but in the focal plane and placing on object in front of a lens is images just like moral produced images just image him and this image can mean media Real or it can be virtual so have a virtual image and the virtual image vendors on the same side of while the real images on the opposite side the difference between lenders and borrowers that these lenses so transmissive system so that wildly Rosa reflective so what corresponds who will be on the same side of the lens this what court orders on the opposite side for him with a bicyclist so thank you very
37:37
much
00:00
Kit car
Refractive index
Visible spectrum
Hail
Year
Interstellar medium
Particle physics
Audio frequency
Light
Primary color
Audio frequency
Refraction
Wavelength
Colorfulness
Transmission (mechanics)
Very low frequency
Rope
Accelerator mass spectrometry
Automobile
Color code
Coir
Last
Airspeed
Microwave
01:44
Theory of relativity
Duty cycle
Order and disorder (physics)
Interstellar medium
Light
Wavelength
Colorfulness
Tool
Rad (unit)
Astronaut
Color code
Atmosphere of Earth
Water vapor
Halpha
Augustus, Count Palatine of Sulzbach
Refractive index
Black
Evening
Answering machine
Light
Wavelength
Cartridge (firearms)
Water vapor
Ruler
System in package
Transmission line
Day
Boat
Year
Star catalogue
Audio frequency
Towing
Reflexionskoeffizient
Refraction
Alcohol proof
Birefringence
Glass
Mail (armour)
Pooltype reactor
Elle (magazine)
Refraction
Fulling
Totalreflexion
Audio frequency
Angle of attack
Sizing
Caliber
Miner
Atmosphere of Earth
08:07
WellenNabenVerbindung
Pooltype reactor
Yellow
Refractive index
Swimming (sport)
Particle physics
Reflexionskoeffizient
Totalreflexion
Angle of attack
Alcohol proof
Atmosphere of Earth
Drill bit
Water vapor
Ground (electricity)
09:54
Fur clothing
Gaussian beam
Hot working
Effects unit
Optical amplifier
Year
Surfacetosurface missile
Cosmic distance ladder
Light
Reflexionskoeffizient
Group delay and phase delay
Gemstone
Spiral galaxy
Refraction
Wavelength
Colorfulness
Alcohol proof
Glass
Steckverbinder
Spare part
Optical fiber
Modulation
Tool
Astronaut
Leistungsanpassung
Diamond
Raft
Star
Capacity factor
Speckle imaging
Field emission microscopy
Refractive index
Fuel injection
Thin film
White
Light
Cable
Refraction
Totalreflexion
Angle of attack
Cartridge (firearms)
Fiber
Micrometer
Binoculars
Caliber
Avalanche
Strapping
Atmosphere of Earth
14:49
Theory of relativity
Halpha
Physicist
Order and disorder (physics)
Particle physics
Cosmic distance ladder
Light
Radio atmospheric
Towing
Refraction
Angle of attack
Direct current
Beta particle
Tool
Caliber
Solar energy
Gamma ray
Tape recorder
Striking clock
17:54
Speckle imaging
Angle of attack
Rain
Curved mirror
19:06
Speckle imaging
Pooltype reactor
Hull (watercraft)
Bomb
Refractive index
Particle physics
Lead
Cosmic distance ladder
Radio atmospheric
Refraction
Roll forming
Cartridge (firearms)
Digital television
Spare part
Plane (tool)
Negation
Month
Caliber
Miner
Water vapor
Water vapor
Atmosphere of Earth
21:26
Hot working
Pooltype reactor
Refractive index
Year
Particle physics
Pair production
Refraction
Roll forming
Friction
Plane (tool)
Tool
Caliber
Water vapor
Atmosphere of Earth
22:14
Nut (hardware)
Quality (business)
Piping
Kilogram
Bookbinding
Minute
Multiplexed Analogue Components
Relative articulation
Mercury switch
Cosmic distance ladder
Light
Plane (tool)
Tool
Atmosphere of Earth
Voyager program
Speckle imaging
Rearview mirror
Augustus, Count Palatine of Sulzbach
Plough
Refractive index
Committee
Light
Florett
Source (album)
Focus (optics)
Excited state
Series and parallel circuits
Exosphere
Sewing needle
Cartridge (firearms)
Fahrgeschwindigkeit
Mintmade errors
Plane (tool)
Flight information region
Willo'thewisp
Refractive index
Year
Umber
Radio atmospheric
Curved mirror
Reflexionskoeffizient
Superheterodyne receiver
Metal
Trainer (aircraft)
Caliper
Spare part
Steckverbinder
Mining
Negation
Ion
Focal length
Cosmic distance ladder
Mail (armour)
Bus
Twoway radio
Couch
Glass
Concentrator
Focal length
Angle of attack
Sizing
Interstellar medium
Caliber
Miner
Last
30:16
Hail
Order and disorder (physics)
Interstellar medium
Relative articulation
Speckle imaging
Cosmic distance ladder
Light
Hall effect
Surfboard
Wavelength
Colorfulness
Stardust (novel)
Coach (bus)
Plane (tool)
Tool
Color code
Speckle imaging
Rearview mirror
Strahlungsnebel
Refractive index
Light
Pair production
Focus (optics)
Food storage
Plane (tool)
Gaussian beam
Day
Particle physics
Audio frequency
Radio atmospheric
Curved mirror
Reflexionskoeffizient
Weather front
Superheterodyne receiver
Refraction
Ship class
Measuring instrument
Glass
Radiation
Dimmer
Month
Mail (armour)
Array data structure
Camera lens
Buick Century
Microscope
Refraction
Fulling
Glass
Focal length
Totalreflexion
Angle of attack
Audio frequency
Sizing
Standard cell
Interstellar medium
Optics
Miner
Atmosphere of Earth
Last