2 Geometrical Optics Pt 2

Light & Optics Unit Becky McCoy

Lesson Title: Geometrical Optics Part 2 Timing: 50 minutes

Target Audience: High School Conceptual Physics Course (9th – 12th grade)

Objectives: Students Will Be Able To: • • •

Identify how light travels. Understand how different materials affect the purpose of a lens. Draw basic diagrams of light traveling through lenses.

The Teacher Will Be Able To: • • •

Identify student misconceptions and prior knowledge. Expose students to the idea of reflection. Help students to discover how different materials affect the way light bends.

Standards Assessed: New York State, The Physical Setting 4.3 viii Draw ray diagrams to represent the reflection and refraction of waves

Misconception(s) Addressed: • • •

Light does not travel. Light does not bounce or reflect. Lenses must be whole to form images.

Prior Knowledge: Basic, everyday working knowledge of light and optics. Aim: Discover and describe how light moves as a ray through lenses. Concept Map Vocabulary: • • • •

Ray Model Reflection Refraction Converging/Convex

• •

Necessary Preparation: COPIES • Royal Observatory Article • List of international telescopes MATERIALS

Lens Diverging/Concave Lens Image

• • • •

Focal Point Focal Length Upright/Inverted Real/Virtual

Light & Optics Unit Becky McCoy • Eye glasses • Camera • Glass bottles • Glass bowls • 2 Clear Plastic Cup • Tupperware • Magnifying Glass • Water • Styrofoam Balls spray painted different colors (one for each group) • Toothpicks (10 for each group) SET UP • Power Point presentation and technology to present. • Stations around the room. • Fill one plastic cup with water.

Light & Optics Unit Becky McCoy

Lesson Plan

Aim: To discover and describe how light moves as a ray through lenses. Physics Push-Up: The Makings of a Telescope (5 min) Students should be separated into small groups and assigned sections of the article “The 28-ince PhotoVisual Refractor.” Each group should share the most important facts from their section of the article with the rest of the class. (http://www.nmm.ac.uk/explore/astronomy-and-time/astronomy-facts/history/the28-inch-photo-visual-refractor/*/viewPage/2)

Activity: Through the Looking Glasses (15 minutes) Materials: • Eye glasses • Camera • Glass bottles • Glass bowls • 2 Clear Plastic Cup • Tupperware • Magnifying Glass • Water • Styrofoam Balls spray painted different colors (one for each group) • Toothpicks Procedure: 1. Stick the toothpicks in Styrofoam ball to create a unique object. 2. At each station, look at your object through the “lens” provided. 3. Record what you observed at each station. Questions to Ask: • Did the color of your object change? • Did the shape appear to change? • Did the toothpicks ever look different? • Was what you observed predictable, or were you surprised?

Activity Summary: Geometrical Optics (20 minutes) Using the second portion of the Geometrical Optics power point (the lens section), explain to students that we can draw ray diagrams with lenses just like we did with mirrors. Don’t be concerned with angle of refraction, just with student understanding of how to draw the diagrams. Introduce the anatomy of a lens and point out that parallel rays intersect at the focal point!

Light & Optics Unit Becky McCoy

Homework: Comparison of Telescopes (5 minutes) Using the nine planets website (http://astro.nineplanets.org/bigeyes.html), students should pick one telescope to compare/contrast to the Royal Observatory telescope. Students should compare and contrast the basic instrumentation of the telescopes as well as the funding and other cultural factors. If students can, they should find pictures taken by the telescopes and compare what the telescopes can see based on their positioning in the world. Mid-Unit Project: Advertising Optical Technology Students should research and choose a piece of optical technology. They should then design an advertisement to be used in a newspaper, magazine, television, or radio commercial. Students should explain their reasoning for choosing their genre of advertisement and use what they have learned in class to market their product.

Exit Strategy: What Would You Use? (5 minutes) Pose the following to students; their answers should be written and submitted: If you were to make a lens to magnify something far away, which material would you use from the activity? Why? (NOTE: students can not answer “camera” or “magnifying glass” because those are already designed to answer the question).

Extension Activity: Allow students to combine different materials and see what their objects look like. Be sure they record their observations.

Assessment: • • •

Student responses throughout activities. Student reasoning in exit strategy. Teacher awareness of student questions and discussions throughout class.

Resources: Bill Arnet’s Astro Website: http://astro.nineplanets.org/bigeyes.html Making Sense of Secondary Science by Rosalind Driver UK National Maritime Museum: http://www.nmm.ac.uk/explore/astronomy-and-time/astronomyfacts/history/the-28-inch-photo-visual-refractor/*/viewPage/2

Notes & Adaptations:

Light & Optics Unit Becky McCoy

Advertising Optical Technology You have just been hired by Bseen, a technology company that specializes in optical technology. You must choose a product to market, design a proposal marketing scheme, and explain your marketing decisions. In order to create a successful campaign, you must include scientific background on your product. This can be information you have learned in class or researched on your own. Assume you are advertising to people who understand optics. You must provide a written explanation of your decisions. You should be clear in communicating why you made those decisions for your proposal. If you are not clear and thorough, your proposal might be rejected. The advertisement you design must be appropriate for one of the following: • Magazine • Newspaper • Radio • Television Your advertisement and written explanation is due Class Four. The rubric for this project is as follows: √+

√

√-

Science Content

Appropriate and wellapplied science content.

Some science content, but not thorough.

Where’s the science?

Creativity/Appeal

Where can I buy it?

Hmm…I might buy it later.

I’m not buying that!

Clarity of Explanation

Decisions clearly communicated and I understand the marketing scheme.

Decisions communicated, but I’ve still got questions.

I don’t understand why you made your decisions and will hire someone else.