Test 2 News Keep your Tests in your notebook but return your Scantron forms and the Manipulative. Keep your Tests in your notebook but return your Scantron forms and the Manipulative. Some of the questions will appear on the comprehensive final. Some of the questions will appear on the comprehensive final. Discuss questions that you missed with your team mates. Discuss questions that you missed with your team mates.

The Plan Locate your name tag. Locate your name tag. Remove the team role name and leave it on the desk in front of you. Remove the team role name and leave it on the desk in front of you. Leave the team name sign on the desk as well. Leave the team name sign on the desk as well. Get ready to move… Get ready to move…

EGR Hands-on XO Gathers Supplies CO Speaks for the Team + Attendance COM Recorder + Chalkboard Remember Attendance Sheets

Chapter 14 & 15 Light and Color

“Inside My Eye” Supplement

Parts of the Human Eye (Supplement Handout) Cornea – bends light Iris – controls the amount of light Pupil - opening Lens – focuses light onto retina Retina – back of eye Fovea – center of your vision Optic Nerve – “signal wire” (causes blind spot) Blind Spot Demo (Page 265) OX

Rods - brightness receptors Cones - color receptors –T–T–T–Three Types: Red, Green, Blue Cones are more numerous in the center of your vision. Rods are more numerous around the periphery of your vision. Demo – Moving markers near periphery

Color Deficiency

Color Vision Colorblindness - about 10% of population Colorblindness - about 10% of population Red-green is predominant Red-green is predominant Yellow-blue - a few Yellow-blue - a few

What is color? Different wavelengths of light are perceived as different colors. Different wavelengths of light are perceived as different colors. White light contains equal amounts of these colors. (ROY G. BIV) White light contains equal amounts of these colors. (ROY G. BIV)

Fill in the Blanks Black objects _______ all of the pure colors. Black objects _______ all of the pure colors. White objects _______ all of the pure colors. White objects _______ all of the pure colors. Transparent objects _______ all of the pure colors. Transparent objects _______ all of the pure colors. absorb reflect transmit

Color Filters Red filters transmit red light and absorb the other colors. Red filters transmit red light and absorb the other colors. Red objects reflect red light and absorb the rest. Red objects reflect red light and absorb the rest. In red light, what color do the red petals and green leaves of rose appear? In red light, what color do the red petals and green leaves of rose appear?

Color Filters Red filters transmit red light and absorb the other colors. Red filters transmit red light and absorb the other colors. Red objects reflect red light and absorb the rest. Red objects reflect red light and absorb the rest. In red light, what color do the red petals and green leaves of rose appear? In red light, what color do the red petals and green leaves of rose appear? –Answers: Petals appear red Petals appear red Leaves appear to be black Leaves appear to be black

Color Filters The following color filters are yours to keep in the zip-lock bags: The following color filters are yours to keep in the zip-lock bags: –Red, Green, Blue –Yellow, Magenta, Cyan

Flashlights All flashlights must work for this exercise.

Mixing Colored Light Color Addition Additive Primary Colors: Additive Primary Colors: Red Red Green Green Blue Blue One can produce any color by varying amplitude and mixture or red, green and blue light. One can produce any color by varying amplitude and mixture or red, green and blue light.

Color Addition Examples: Color Addition Examples: –Tiny dots called pixels on Color TV's and Computer Monitors are colored only red, green, or blue. –“Color Addition” Lab Exercise (two pages) Lab Exercise (two pages) –Color Addition Equations

Remember Attendance Sheets (Role Rotation) EGR Hands-on XO Gathers Supplies CO Speaks for the Team + Attendance COM Recorder + Chalkboard

Lab Exercises “White Light” and “Color Addition Wheels” “White Light” and “Color Addition Wheels” –Everyone will color Roy G. Biv onto the 7 segment wheel. –XO Red + Blue = ? –CORed + Green = ? –ENGBlue + Green = ? –COM Red + Blue + Green = ?

Mixing Colored Pigments Color Subtraction Subtractive Primary Colors: Subtractive Primary Colors: Yellow Yellow Magenta Magenta Cyan Cyan One can produce any color by varying the amount of yellow, magenta and cyan pigments. One can produce any color by varying the amount of yellow, magenta and cyan pigments.

Color Subtraction Examples: Color Subtraction Examples: –Newspapers, magazines, books –Zip-lock with colored seals –“Color Subtraction” Lab Exercise (two pages) Lab Exercise (two pages) –Color Subtraction Equations

Color Subtraction Using Crayons Lab Exercise

Chromatography

White Red Green Blue Yellow Cyan Magenta Primary Colors

Green Pure Green Color Addition Primary Green

Complementary Colors - any two colors that add together to produce white Complementary Colors - any two colors that add together to produce white e.g. magenta + green = white e.g. magenta + green = white

Physics Engineering Astronomy

And our flag was still there...

Spiral

After Images and “Conal Fatigue” The human eye will see complimentary colors after staring at a color picture. The human eye will see complimentary colors after staring at a color picture. Demos: Demos: Colored Shapes Colored Shapes Texas Flag Texas Flag American Flag American Flag Rose Rose Lincoln Lincoln

Lab Supplement Color a Flag with Complementary Colors Color a Flag with Complementary Colors –Move this page forward –What color would we use so that the afterimage is red, white and blue? –Write this on the supplement: Complementary Colors Complementary Colors Use cyan, black, and green get an after image that is red, white and blue. Use cyan, black, and green get an after image that is red, white and blue.

Optical Illusions Animation Animation

Transparent and Opaque (14.2) Transparent you can identify objects through it Translucent you see diffuse light coming through it Opaque you cannot see any light coming through it Opaque objects cast shadows.

“Can Light Pass Through” Lab Exercise

“Transparency” Lab Exercise

“Pattern for Flashlight Reflector Shield” Lab Exercise Why? We want a point source of light rather than a beam when we investigate the shadows created by opaque objects.

“Tall in the Shadow” Lab Exercise

Chapter 18 Spectra

The Electromagnetic Spectrum A range of light waves extending in wavelength from radio waves to gamma rays

The Electromagnetic Spectrum On Chalkboard

The Electromagnetic Spectrum Radio Waves Microwaves Infrared Visible Light Ultraviolet X-rays Gamma Rays               Which form of light has the …longest wavelength? …highest frequency? …highest energy? …fastest speed?

The Electromagnetic Spectrum Radio Waves Microwaves Infrared Visible Light Ultraviolet X-rays Gamma Rays Raging Martians Invade Roy G. Biv Using X-rays and Gamma Rays mnemonic

Radio Waves

Microwaves

Infrared

Visible Light

Ultraviolet

X-Rays

Gamma Rays

SPF The SPF of a sunscreen is a laboratory measure of the effectiveness of sunscreen; the higher the SPF, the more protection a sunscreen offers against UV-B (the ultraviolet radiation that causes sunburn). The SPF of a sunscreen is a laboratory measure of the effectiveness of sunscreen; the higher the SPF, the more protection a sunscreen offers against UV-B (the ultraviolet radiation that causes sunburn).sunburn The SPF indicates the time a person can be exposed to sunlight before getting sunburn with a sunscreen applied relative to the time they can be exposed without sunscreen. The SPF indicates the time a person can be exposed to sunlight before getting sunburn with a sunscreen applied relative to the time they can be exposed without sunscreen. For example, someone who would burn after 12 minutes in the sun would expect to burn after 2 hours (120 min) if protected by a sunscreen with SPF 10. For example, someone who would burn after 12 minutes in the sun would expect to burn after 2 hours (120 min) if protected by a sunscreen with SPF 10.

The Visible Spectrum A range of light waves extending in wavelength from about 400 to 700 nanometers.

Things that create a Spectrum Prism Raindrops CD’s Spectroscopes Contains a Diffraction Grating

Diffraction Grating for Ziplock Bag

Creating a Spectroscope Roll up and tape black paper to form a tube. Cover end of the tube with foil. Use a blade to make a slit in the foil. Temporarily tape the diffraction grating over the other end of the tube. Observe several light sources. Incandescent Light, Florescent Light, Neon Sign

Object Names Blue Bowl Red Bowl Yellow Post-it Orange Post-it

Object Names Red Filter Green Filter Yellow Filter Cyan Filter

Robert BunsenGustav Kirchhoff “The Taste Test” versus “The Flame Test”

Continuous Spectra Hot, dense solids produce a continuous spectrum. (All Colors)

Hot gas produces a bright line emission spectrum. (Bright Lines) Emission Spectra

Filters behind continuous sources give absorption spectrum. (Missing Colors) Absorption Spectra

Example Questions What type of spectra do each of the following have? Flashlight bulb Frosted Incandescent lamp Neon Sign Florescent light Red bowl Hot Solids Hot Gasses Cool objects that reflect light

Structure of the Atom Proton Neutron Electron Energy Levels

Absorption When an electron is raised to a higher energy level, the atom is said to be excited.

Emission When the electron returns to a lower energy level, energy is released in the form of light.

Different transitions from high levels to low levels result in different colors of light. Every element can be “fingerprinted” by it spectra. “Element Fingerprinting”

Helium Hydrogen Oxygen Carbon Every element can be “fingerprinted” by it spectra.

Matching Questions Type of SpectrumAppearance 1. Emission Spectraa. All Colors 2. Continuous Spectrab. Dark Lines 3. Absorption Spectrac. Bright Lines

Matching Questions 1. Emission Spectraa. Hot Solids 2. Continuous Spectrab. Cool Solids 3. Absorption Spectrac. Hot Gases

The color of light emitted by hot glowing solids changes with its temperature. Glowing object colors: Reddish  coolest glowing object Orange-ish Yellowish White Bluish  hottest glowing object Incandescence

Example Questions The star Sirius is blue and Arcturus is yellow. Which is hotter? Answer: Sirius, I’m not kidding. Consider a red filter and a blue filter. Which is hotter? Answer: They should be the same temperature because they are not “glowing”.

Fluorescence Some materials that are excited by ultraviolet light can emit visible light upon de-excitation. This is fluorescence. Demo - Black light and chalk

Fluorescent Lamps Primary excitation - electron collisions with low pressure mercury vapor, and ultraviolet light is given off Secondary excitation - ultraviolet light is absorbed by phosphors and these emit visible light

Phosphorescence Phosphorescence - a type of light emission that is the same as fluorescence except for a delay between excitation and de- excitation. Electrons get "stuck" in an excited state and de-excite gradually. Demos - glow-in-the-dark objects

Lasers Laser Light amplification by stimulated emission of radiation Lasers produce coherent light. Coherent light means that all the light waves have the frequency, phase and direction. Demo - Laser and chalk dust Demo - Laser and prism or diffraction grating

Matching Questions 1. Incandescencea. mercury vapor light tubes 2. Fluorescenceb. glow-in-the-dark paints and plastics 3. Phosphorescencec. light bulbs with filaments

Matching Questions 1.Fluorescent Lampa. color changes with temperature 2.Incandescent Bulbb. only one color of light 3. Laserc. converts ultraviolet light to visible light

Law of Reflection “The angle of incidence equals the angle of reflection.” This is true for both flat mirrors and curved mirrors. Convex Mirror - security mirror Concave Mirror - vanity mirror Demo: Chalk Dust and Concave Mirror

Types of Reflection Specular Reflection - images seen on smooth surfaces (e.g. plane mirrors) Diffuse Reflection - diffuse light coming from a rough surface (cannot see a reflection of yourself) Movie

Reflection Demonstrations Candle in Water Video (Movie)Movie Terminator II Movie

Supplemental Handouts Funny Face Reverse Images Make a Kaleidoscope

EGR Hands-on XO Gathers Supplies CO Speaks for the Team + Attendance COM Recorder + Chalkboard Please bring your book to class tomorrow.

Notebooks Due on Wednesday before the Exam. Due on Wednesday before the Exam /homework/NOTEBOOK.doc 410/homework/NOTEBOOK.doc 410/homework/NOTEBOOK.doc 410/homework/NOTEBOOK.doc

Principle of Least Time Fermat's principle - light travels in straight lines and will take the path of least time MIRROR AB Wrong Path True Path

Refraction Refraction is the bending of light when it passes from one transparent medium to another. This bending is caused by differences in the speed of light in the media. WATER WAVE MOVIE

Refraction WATER AIR Normal Line Fast Slow Light Beam

Refraction Examples Light slows down when it goes from air into water and bends toward the normal. An Analogy: A car slows down when it goes from pavement onto gravel and turns toward the normal. MOVIEMOVIE Index of Refraction n=c/v

Refraction WATER AIR Observer True Fish False Fish

Lab Exercises “Refraction” Cup of Water and Pencil Broken Pencil Movie “Finding Object Under Water” “Refraction Activities” Procedure 1 - Shallow Appearance Procedure 2 - Spearing a Fish Procedure 3 - Broken Images

Dispersion... …is the separation of white light into pure colors (ROY G. BIV). Dispersion Examples: Prisms Diffraction Gratings

Rainbows Raindrops refract, reflect and disperse sunlight. Rainbows will always appear opposite of the Sun in the sky. You cannot run from or run to a rainbow! How can you make a rainbow?

Remember Attendance Sheets (Role Rotation) EGR Hands-on XO Gathers Supplies CO Speaks for the Team + Attendance COM Recorder + Chalkboard

Lenses Converging Lens A lens that is thicker in the middle and refracts parallel light rays passing through to a focus. Diverging Lens A lens that is thinner in the middle than at the edges, causing parallel light rays to diverge. Team Exercise: Lens sorting

Myopia (Near-Sightedness) People with near-sightedness cannot see clearly at distance. What kind of corrective lens will they need?

Hyperopia (Farsightedness) People with far-sightedness cannot see clearly up close. What kind of corrective lens will they need?

“Where is the Image?” Lab Exercise

“Making a Telescope” Lab Exercise

Total Internal Reflection... …is the total reflection of light traveling in a medium when it strikes a surface of a less dense medium Demo - Laser and light pipe Example: Optical Fiber Ring Laser Underwater Movie Woman Edge Pool Movie

WATER AIR Light Source Critical Angle Total Internal Reflection

Atmospheric Refraction Our atmosphere can bend light and create distorted images called mirages. Mirage 1.mpg What causes stars to twinkle? Atmospheric Turbulence

Mirage Warm air Cool air

Earth Sun Because of atmospheric refraction, we have lingering, elliptical sunsets.

Why is the sky blue? Nitrogen and Oxygen in our atmosphere scatter high frequencies of light. Nitrogen and Oxygen in our atmosphere scatter high frequencies of light.

Why are sunsets red? Red light is scattered the least by our atmosphere. Red light is scattered the least by our atmosphere. The greatest path of sunlight through the atmosphere is at sunset or sunrise. The greatest path of sunlight through the atmosphere is at sunset or sunrise.

Why are clouds white? The color of light scattered by clusters of water molecules vary with the size of the clusters. The color of light scattered by clusters of water molecules vary with the size of the clusters. The size of clusters of water molecules (droplets) vary in clouds. The size of clusters of water molecules (droplets) vary in clouds.

Why is the ocean greenish blue? Red light is absorbed by the molecules in the water. Red light is absorbed by the molecules in the water.

Review for Test 3 Chapter 14 Chapter 14 –Color Chapter 15 Chapter 15 –Refraction Chapter 18 Chapter 18 –Spectra

Chapter 14 Section 14.3 through 14.8 Section 14.3 through 14.8 –Selective Reflection –Selective Transmission –Color Addition –Color Subtraction –Complementary Colors –Conal Fatigue –Why is the sky blue? –Why Sunsets are Red

Chapter 15 Section 15.2 through 15.6 Section 15.2 through 15.6 –Refraction - Bending –Speed in different media –Apparent Water Depth –Illusions and Mirages –Atmospheric Refraction –Dispersion –Rainbows –Lenses and Telescopes –Your Eye –Image Formation

Exercises Bob the Builder and Filter Glasses Bob the Builder and Filter Glasses “Goggles” - Supplement “Goggles” - Supplement “Kaleidoscope” “Kaleidoscope” “Animal Shadow” “Animal Shadow” “Prism Power” “Prism Power” Chromatography Chromatography

Diffraction a modification which light undergoes in passing by the edges of bodies or through narrow slits …and in which the rays appear to be deflected and to produce fringes of parallel light and dark or colored bands Water Wave Interference Movie Multiple Slit Interference Movie

How to Study Read the chapters in the syllabus and focus on the topics covered in class. Chapter 13 - Waves and Sound Chapter 14 - Light and Color Chapter 18 - Atomic Models Chapter 15 - Reflection and Refraction Review your notes and class exercises. Use the access code on the inside cover you’re your book to gain access to example questions and flashcards online.

Doppler Effect the change in wavelength due to motion of the source or observer "Wheeeeeeeeeeee…….Oooooooooooooo” Examples: Water, Sound, and Light

Source at Rest Wavelength

What happens when the source in in motion? Movie #1 Movie #1 Java

Source in Motion Short Wavelength High Frequency High Pitch Weeeeeeeee!!! Long Wavelength Low Frequency Low Pitch Ooooooo!!! As a team, describe what happens to the wavelength, frequency, and pitch both in front of and behind a moving sound source.

Doppler Effect Examples: moving cars and trains Sound Movie #2 moving buzzer in a nerf ball (in class)

Chapter 14 & 15 Light and Color Be prepared to turn in your notebook at the beginning of Test 3. It will be returned at the end of Test 3. Please keep your notebook after that for your future class.

Test 3 Everyone starts Test 3 at 1pm. Everyone starts Test 3 at 1pm. Manipulative Manipulative –Transparent, Translucent, Opaque –Spectra, Color, and Lenses –Pendulum (Optional)

The Electromagnetic Spectrum Radio Waves - communication Microwaves - used to cook Infrared - felt as warmth Visible Light - detected by your eyes Ultraviolet - causes sunburns X-rays - penetrates tissue Gamma Rays - most energetic .      .      ROYGBIVROYGBIV Mnemonic? Raging Martians Invade Roy G. Biv Using X-rays and Gamma Rays

EGR Hands-on XO Gathers Supplies CO Speaks for the Team + Attendance COM Recorder + Chalkboard Remember Attendance Sheets

Remember Attendance Sheets Your view… EGR Hands-on XO Gathers Supplies CO Speaks for the Team + Attendance COM Recorder + Chalkboard

Chapter 14 & 15 Light and Color

Remember Attendance Sheets (Role Rotation) EGR Hands-on XO Gathers Supplies CO Speaks for the Team + Attendance COM Recorder + Chalkboard

Remember Attendance Sheets (Role Rotation) EGR Hands-on XO Gathers Supplies CO Speaks for the Team + Attendance COM Recorder + Chalkboard

Remember Attendance Sheets (Role Rotation) EGR Hands-on XO Gathers Supplies CO Speaks for the Team + Attendance COM Recorder + Chalkboard

Remember Attendance Sheets (Role Rotation) EGR Hands-on XO Gathers Supplies CO Speaks for the Team + Attendance COM Recorder + Chalkboard