Today’s Class! Turn in MOPS. They are due today. Pick up a new set of class notes and assignment sheet. What is our new topic? To Do Work on your project Spectrum Web Quest due Thursday Class Today New Unit, New Plan Sound vs. Light Polarization Phys Tues. 5/7/13

Sound Longitudinal pressure wave in air or other medium Speed v = f λ depends on medium Frequency = pitchAmplitude = loudness Properties = constructive and destructive interference, reflection, standing waves, nodes, antinodes, Doppler shift of frequency for moving source or observer

Light Transverse wave of electromagnetic radiation Speed c = f λ depends on medium, is constant in a vacuum Requires NO mediumc = 3.00 × 10 8 m/s in vacuum Frequency = colorAmplitude = brightness Properties = constructive and destructive interference, reflection, standing waves, nodes, antinodes, Doppler shift of frequency for moving source

Polarization: Alignment of Electric Field Wave

Polarizing Filters Activity How do you think sunglasses work? How do they reduce glare? Why are some better than others? Look through the polarizing filters at your table and see if they can help you answer the questions in your class notes. Class notes, p. 6

Today’s Class HPhys Weds. 5/8/13 Pick up a new set of class notes and assignment sheet. What is our next topic? What is a SPECTRUM? Class Today Missing Work Spectrum Web Quest Project Conferences

Today’s Warm-up “Light travels faster than sound. This is why some people appear bright until you hear them speak.” What kind of wave? Class Notes, Page 3  To Do Start Problem Set LO-1 Finish Spectrum web quest Project Progress report #1 Due Friday 5/2 (TOMORROW) Phys Weds. 5/8/13Phys Thurs 5/1/14

Today’s Warm-up “Light travels faster than sound. This is why some people appear bright until you hear them speak.” How are light and sound the same? How are they different? To Do Start Problem Set Finish Spectrum web quest Project Progress report #2 Due MONDAY 5/20 HPhys Thurs. 5/9/13 What kind of wave? 

Today’s Warm-up Solve this problem on p. 5 of your class notes: A microwave oven has a frequency of 2450 MHz. What is the wavelength of this light? To Do Project Progress report #2 Due next MONDAY! Phys Thurs. 5/9/13

Standing waves in a microwave oven Traveling waves are reflected by the sides of the oven. The size of the oven is chosen to make a standing wave pattern. Antinodes have maximum amplitude and nodes have zero amplitude.

Four Ways to Bend Light (which usually travels in straight lines) Reflection = Bouncing off a surface (like mirrors) Refraction = Changing speed at interface of two media (like lenses) Diffraction = Constructive and destructive interference (around small objects or apertures) Scattering = Bouncing off small particles (like smoke or water droplets)

Scattering Light bounced off small particles in all directions Size of particles is comparable to wavelength of light

Today’s Class! Finish the Problems on p. 6 of your class notes. Look at the KEY QUESTIONS on the front of your class notes. How many can you answer? To Do Work on your project this weekend! Class today 4 ways to bend light Scattering Demo Start Diffraction Mini Lab H PHYS Friday 5/10/13

Diffraction Interference Applet Light bends around edges or as it passes through a slit. Wave interference causes a characteristic pattern of stripes or bullseye

Single Slit Interference Path Difference: Two beams from each side of slit travel different distances, to reach a point at an angle, on a screen.

Constructive and Destructive For a minimum: 2 waves destructively interfere, path difference is ½ λ  m For a maximum: 2 wave constructively interfere, path difference is λ  m

Today’s Class! Turn in your problem set, if you are done with it. It is due at the end of the day. Review with the LAST PAGE of your class notes. Look at the KEY QUESTIONS on the front of your class notes. Can you answer them? We will go over the answers, then take the Light Quiz #1 To Do Work on your project! Class today Review and catch up Quiz #1 Start Diffraction Mini Lab PHYS Friday 5/10/13

Today ’ s Warm-up Take out your problem set Do you have questions? What happens when light passes through a small opening or around a small object? Why??? Coming up Tues: Problem Set due Weds: Diffraction Mini Lab due Friday: Mastery Quiz #2 Problem Set 23 due NEXT MON: Project progress report due Hphys Monday 5/13/13 Today’s Class Mastery Quiz #1 Finish Diffraction Mini Lab Law of Reflection

Today ’ s Warm-up Take out your Diffraction Mini Lab and get to work! What happens when light passes through a small opening or around a small object? Why??? Coming up Tues: Diffraction Mini Lab due Weds: Mastery Quiz #2 Friday: Problem Set LO-2 due, Q#3 NEXT MON: Project progress report due Phys Monday 5/13/13 Today’s Class Finish Diffraction Mini Lab Law of Reflection

Today ’ s Warm-up Take a flat mirror and use it to look at the person next to you. What path does the light from the person next to you take to get to your eye? Can you say anything about the angles at which the light hits and leaves the mirror? Coming up Today: Problem Set due Weds: Diffraction Mini Lab due Friday: Mastery Quiz #2 Problem Set 23 due NEXT MON: Project progress report due Hphys Tuesday 5/14/13 Today’s Class Law of reflection Plane Mirrors Concave and Convex Mirrors

Today ’ s Warm-up Take a flat mirror and use it to look at the person next to you. What path does the light from the person next to you take to get to your eye? Can you say anything about the angles at which the light hits and leaves the mirror? Coming up Today: Diffraction Mini Lab due Weds: Quiz #2 Friday:Problem Set LO-2 due Mastery Quiz #3 Phys Tues. 5/14/13 Today’s Class Law of reflection Plane Mirrors Concave and Convex Mirrors

Specular vs. Diffuse Reflection Mirror or smooth surface Rough surface reflects in all directions

Law of Reflection Angle of Incidence = Angle of Reflection Bill Nye on Mirrors

Virtual Images Appear behind a mirror, right side up Happen because of our brain’s ability to track light traveling in straight lines.

Plane Mirrors Ray Diagram follows Law of Reflection θ incidence = θ reflection Plane Mirror Applet Virtual image: Seen behind mirror, not the result of light rays meeting in space Real image: Can be seen on a screen or paper, result of light rays meeting

Spherical Mirrors Concave = Converging Parallel rays form real image at focus Radius of curvature r = 2 f REAL image forms where light rays meet. Real images can be focused on a screen.

Spherical Mirrors Concave = Converging Ray Diagram: Parallel ray from object to mirror, reflects through f Ray from object through f, reflects parallel Ray straight through center of curvature Lens and Mirror Applet

Spherical Mirrors Convex = Diverging Virtual image formed behind the mirror

Spherical Mirrors Lens and Mirror Applet Convex = Diverging Virtual image formed behind the mirror Ray Diagram: Parallel ray from object to mirror, reflects through f Ray from object through f, reflects parallel Ray straight through center of curvature

Today ’ s X-Day 1.Complete and turn in Diffraction Mini Lab 2.Make up missing work. 3.Work on your project. Conference with Dr. Hair. 1.Go over your Waves and Sound Test. 2.Start Problem Set 23 To Do Problem Set 23 Project PRoJeCt PROJECT! Hphys Weds. 5/15/13

Today ’ s X-Day 1.Take Quiz #2. 2.Complete and turn in Diffraction Mini Lab 3.Work on your project. Conference with Dr. Hair. 1.Go over your Waves and Sound Test. 2.Start Problem Set LO-2 To Do Problem Set LO-2 Project PRoJeCt PROJECT! Phys Weds. 5/15/13

Today ’ s Warm-up Why is this person upside down? What could they do to make themselves right side up? To Do Prob Set Due MONDAY Mastery Quiz MONDAY PROJECT! Progress Report #2 due MONDAY! Today ’ s Class Reflection Review Problem Set Q & A Go over Wave Test Refraction Intro Thursday 5/16/13

Refraction Mini Lab Day with Substitute while at 6 Flags

Today’s Class Check out the pencil in a glass of water. What phenomenon is this? Why is light BENDING and what does this do to your view of the pencil? Monday 5/20/13 Class Today Refraction overview Refraction Mini Lab Q&A Next Quiz To Do Turn in Project Progress Report #2 Problem Set due, MOPS due tomorrow QUIZ on Light and Optics Today Bill Nye on Refraction

Refraction Light changes speed when it moves from one medium to another. Fermat ’ s Principle of Least Time says that light will travel through the two media in a path that minimizes the time of travel. This causes it to bend. Reflection and Refraction Applet Minute Physics: Why does light bend?

What is the path that takes LEAST TIME?

Index of Refraction If the index of refraction of plexiglass is 1.51, what is the speed of light in plexiglass? Fermat ’ s principle of least time

Snell ’ s Law Law of Refraction Relates angle of incidence to angle of refraction If a light beam hits a plate of glass with an angle of incidence of 60º, what is the angle of refraction? (n glass =1.52, n air =1.00)

Total Internal Reflection Happens when light passes from media of higher to lower index of refraction. If θ 2 = 90º refracted beam skims the surface θ 1 is called the critical angle. If light passes from water to air, what is the critical angle? (n water =1.33, n air =1.00)

Dispersion Spreading white light into separate colors. Index of refraction varies with wavelength! Rainbows as refraction

Today’s Warm-up Pick up a NEW handout with TODAY’S activity. What are we going to do next? Read it and see! To Do Any missing work, including Diffraction mini lab Refraction mini lab Project Progress Report Light and Optics Quest RETAKE on FRIDAY How is YOUR PROJECT?! Hphys Tuesday 5/21/13

Today’s X-Day Ask Questions before the quiz, if you have any. Take the QUIZ (#3 Mastery) Check to see if you have any missing work. If so, please do it! Check the calendar for what happened in yesterday’s class, if you missed it. Finish your Refraction Mini Lab and turn it in. It is due WEDNESDAY. Have a conference with Dr. Hair about your project. To Do Finish Refraction Lab Mastery Quizzes retake on FRIDAY Phys Tuesday 5/21/13

Today’s Warm-up! When light moves from air to glass or water, is the angle of refraction greater or less than the angle of incidence? What equation tells you how these angles are related? To Do Read Chapters 22 & 23 Problem set due Thursday Finish Lab for Wednesday Quest on Thursday Class today Refraction Review Diffraction concepts Path difference Macro Waves Alpha Tuesday 5/15/12

Today’s Warm-up! When light moves from air to glass or water, is the angle of refraction greater or less than the angle of incidence? What equation tells you how these angles are related? To Do Read Chapters 22 & 23 Problem set due Thursday Finish Lab for Wednesday Quest on Thursday Class today Refraction Review Macro Wave Interference Diffraction concepts BETA Weds. 5/16/12

Today’s X-Period! Finish your Index of Refraction Lab. It is due at the end of the school day. Today is the last work time in class for the lab. Look at this picture, since it will help you with the lab questions. Alpha Weds. 5/16/12 Update your calendar Lab due Today Problem set due THURSDAY Quest on Light and Optics THURSDAY! Progress Report 2 due next Weds. Go over your Mastery Quiz Make up any Missing Work! Have a project conference.

Following Slides Not Used in 2012

Today ’ s Class is a Work Day Please use your time well. Work on the problem set, due tomorrow. Review for tomorrow ’ s quiz on light. Test bridge beams or glues. Work on your project. Meet with Dr. Hair about your project. Weds. 5/11/11

Friday 5/13/11 Today’s Warm-up Take out your class notes and a textbook and define the terms on page 5 or 6 of your class notes. Be prepared to share what you write with the class. Class today Define Terms, review Focus on Refraction Fermat ’ s Principle Index of Refraction Snell ’ s Law Total Internal Reflection Practice refraction calculations To Do Start next problem set/chapter Work on your project!

Focusing with a Lens Lens and Mirror Applet Thin Lens Ray Diagrams Ray Diagram: Parallel ray from object to lens, refracts through f Ray from object through f, refracts parallel Ray straight through lens

What about this lens? How can you tell this is a real image? Where is the focal length of this lens?

Today ’ s Class is an X-Review Day 1.Complete and turn in Missing Work. 2.Turn in your Project Progress Report 2 3.Work on the problem set (due tomorrow). 4.Go over previous tests and quizzes 5.Prepare for tomorrow ’ s Mastery Quiz on Waves + Light and Optics Quest To Do Prob Set 22 & 23 (Due Tomorrow) Test on Light and Optics Tomorrow! PROJECT! Tues. 5/24/11

Test Today! Turn in your problem set in the box in the front of the classroom. Sit down with your calculator, pencil, and ruler. When you are ready, Dr. Hair will bring you a test. Weds. 5/25/11

Today ’ s X- Day 1.Take care of any missing work or quizzes. Pick up graded work and check you current grade in physics. 2.Meet with Dr. Hair about your project. 3.Meet with Dan about your catapult, projectile, or circuit. 4.Turn in your PROJECT PROGRESS REPORT #2. This is your ticket to leave. 5.Do the Light Reality Check. To Do YOUR PROJECT! Light Reality Check

Mirror Equation For Real Image d image is positive For Virtual Image d image is negative

Radio Radio Frequencies AM = Amplitude modulation kHz FM = Frequency modulation MHz TV = Frequency modulation MHz Cell phones = MHz

Diffraction Through a Slit Activity Place blank sheet of paper on foam board and pin it down. Make dots 2 cm apart. This is the width of a slit that light passes through. Using pins, secure 2 strips of light wave A (or B) through the circles on the waves and the dots. Make sure the A’s (or B’s) are both facing the same way. Draw line representing a screen, far from the slit. Move waves to make constructive and destructive interference on the screen. Mark where waves are in phase (constructive) and out of phase (destructive) on screen Do the waves travel the same distance to the screen? What is the path difference? What will the light look like when there is constructive interference? Destructive interference?