15.1 refraction pp. 562 -567 mr. richter. agenda warm-up introduction to refraction demo ...
TRANSCRIPT
![Page 1: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/1.jpg)
15.1 Refractionpp. 562 -567
Mr. Richter
![Page 2: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/2.jpg)
Agenda
Warm-Up
Introduction to Refraction Demo
Reminder: Quarter 3 Ends Friday
Notes: Refraction Index of Refraction Why Light Bends Refracted Images Snell’s Law
![Page 3: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/3.jpg)
Objectives: We Will Be Able To…
Recognize situations in which refraction will occur.
Identify which direction light will bend when it passes from one medium to another.
Solve problems using Snell’s law.
![Page 4: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/4.jpg)
Warm-Up:
When a pencil is partially submerged, it looks like it bends at the surface of the water.
What is really happening?
![Page 5: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/5.jpg)
Refraction
![Page 6: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/6.jpg)
Refraction
When light encounters a boundary, some of the light is reflected and, depending on the boundary, some of the light is refracted.
Refraction is the bending of a ray of light as it passes from one boundary to another.
When light is absorbed, it is not refracted.
![Page 7: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/7.jpg)
Refraction
The angle of refraction θr (how much the light bends) depends on:
The media (materials) through which the light travels
The angle at which light strikes the boundary
![Page 8: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/8.jpg)
Refraction
Your book says: “Refraction occurs when light’s velocity changes”
WRONG! OMG!
Light always travels at the speed of light, no matter what.
However, it gets absorbed and reemitted more in some mediums than others, so its “net speed” can be lessened.
![Page 9: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/9.jpg)
Index of Refraction
![Page 10: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/10.jpg)
The Index of Refraction
Every material bends light a different amount.
The material’s index of refraction of a material indicates how much light will be bent passing through that material.
The index of refraction of a medium is the ratio of the speed of light in a vacuum to the “speed” of light through the medium.
![Page 11: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/11.jpg)
The Index of Refraction
Note the indices of refraction to the right (p. 564).
Air bends light very little, while diamonds bend light very well. Higher index =
more bending!
No indices below 1.
![Page 12: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/12.jpg)
Wavelength and Refraction
Table 15-1 is only valid for wavelengths of 589 nm in a vacuum.
Different wavelengths have different indices of refraction.
This is why white light separates in a prism. Different colors have different wavelengths.
![Page 13: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/13.jpg)
Why Light Bends
![Page 14: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/14.jpg)
Index of Refraction: Why Light Bends
Imagine your right arm as a wave.
As you walk, your arm moves with you through the air.
However, if you drag your hand along a fence, your arm drags behind, bending your body.
![Page 15: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/15.jpg)
Index of Refraction: Why Light Bends
The same thing happens with waves of light.
As wave fronts encounter a new material, they will slow down (or speed up), bending the wave.
![Page 16: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/16.jpg)
Refracted Images
![Page 17: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/17.jpg)
Refracted Images
Objects appear to be at different positions due to refraction.
If light coming from the object (incident) goes to material with a lower index of refraction, the object appears farther from the normal line.
If ni > nr, then θi < θr
![Page 18: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/18.jpg)
Refracted Images
The waves of light leaving the fish travels at one angle.
But as the light hits the boundary (air to water), part of the wave can move faster.
This changes the angle of the light that the cat sees, making the fish appear farther from the normal line. And higher up.
![Page 19: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/19.jpg)
Refracted Images
If light coming from the object (incident) goes to material with a higher index of refraction, the object appears closer to the normal line.
If ni < nr, then θi > θr
![Page 20: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/20.jpg)
Snell’s Law
![Page 21: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/21.jpg)
Snell’s Law
Snell’s law determines the angle of refraction based on: the angle of incident light the indices of refraction from the two different media
![Page 22: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/22.jpg)
Practice Problem
A light ray traveling through air strikes a smooth slab of crown glass at an angle of 30.0° to the normal. Find the angle of refraction, θr.
Given: θi = 30.0°
ni = 1.00
nr = 1.52 (Table 15-1)
Calculations: θr = 19.2°
![Page 23: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/23.jpg)
Wrap-Up: Did we meet our objectives?
Recognize situations in which refraction will occur.
Identify which direction light will bend when it passes from one medium to another.
Solve problems using Snell’s law.
![Page 24: 15.1 Refraction pp. 562 -567 Mr. Richter. Agenda Warm-Up Introduction to Refraction Demo Reminder: Quarter 3 Ends Friday Notes: Refraction](https://reader035.vdocuments.site/reader035/viewer/2022062722/56649f335503460f94c501fe/html5/thumbnails/24.jpg)
Homework
p. 567 #1-4