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Topic
Rationale
Curriculum
Prerequisite Skills
Needed Resources
Schedule
Handouts
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Topic:

The concept of refraction is important to students because it occurs in their everyday lives. Students are familiar with prisms and have a basic understanding of how light bends and disperses as it passes through prisms and water. As well, refraction and total internal reflection are the foundations for many applications of light and waves: rainbows, mirages, fiber optics, polar bear fur.

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Rationale for using this topic as a web quest:

This topic makes a good web quest for two reasons. First, it is not a completely new or difficult theme. Students already have a basic understanding of refraction from elementary science classes and from everyday observations. They would have already looked at the refraction of water waves in an earlier lab. So this is a concept that they can build on independently.

As well, nothing is lost by doing the Snell’s Law lab through a computer simulation. In some cases, computer simulations give too perfect of an answer and students are unable to truly understand or visualize the physical occurrence. But when this experiment is done with lab equipment (a light box, or even straight pins and cardboard), this lab would give extremely accurate results. Concepts such as lose of energy due to friction, importance of accurate weighing or conversion of units is not an issue in this lab.

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Curriculum:

The curriculum guide for this course can be located at:

http://www.sasked.gov.sk.ca/docs/physics/sq20phy.html

The specific topic concepts and objective can be found at:

Refraction: http://www.sasked.gov.sk.ca/docs/physics/u3c12phy.html
Snell’s Law: http://www.sasked.gov.sk.ca/docs/physics/u3c12phy.html
Total Internal Refraction: http://www.sasked.gov.sk.ca/docs/physics/u3c22phy.html

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Student Prerequisite Skills:

The learners for this web quest will be students of a Physics 20 class. The topic of the web quest will be refraction and Snells’s law, a topic in the core unit: Light. The students should already have studied the characteristics of light and the properties of wave motion. They should be familiar with the concept of refraction as it applied to water waves.

It is suggested that the necessary math be done as an independent review prior to the beginning of the unit. The topics to cover should include: manipulation of equations, solving variables, working with fractions and review of trigonometric functions.

In order to manipulate through the web quest the students will need to be able to maneuver through a web site via clicking on links. They will also need to understand how to use the back button to get back to the web quest as they will be visiting sites outside of the web quest. They should also know how to download and print files.

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Needed Resources:

Students will need access to:

  • A computer with
    • internet access
    • a printer
    • A web browser (Internet Explorer, Netscape, Mozzilla, etc.)
    • Acrobat reader ... for the worksheet
    • Java Applet
  • A calculator
  • An instructor to monitor progress and assist with questions.

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Schedule:

The web quest consists of 3 parts:

Part 1 looks at the concept of refraction. Students will read several web pages from the Physics Classroom web site. As they go through the pages they will take guided notes based on a hand-out. They will then work through more advanced theory and application problems. No formal evaluation will occur for this portion of the web quest, but a review of concepts and answers is highly recommended. It should be planned for this portion to take 2 1-hour class periods.

In part 2 students will use an on-line simulation to investigate the direction of a light ray as it passes from one medium into another. The simulation allows students to change the angle of incidence and the indices of refraction of the two mediums. The simulation will display the corresponding angle of refraction and the critical angle where appropriate. Again, students will be given a hand-out with the procedure they are to follow and synthesis questions. The students will hand in a completed lab and will be marked against the given rubric. It is suggested that 2 1-hour class periods be given to this part.

In part 3 students will investigate one of the following applications of refraction: diamond cutting, fibre optics, mirages or binoculars/periscopes. The students will work in groups of 3 - 4. They will research their topic, create a poster to document their findings and present their information to the class. They will be evaluated on their poster and presentation. It is suggested that 2 1-hour classes be given for research. Give the students a few days to put together the poster and prepare their presentation; this should be done on their own time (lunch, afterschool, weekend). Then plan for presentations (this will vary depending on the size of your class - approximately 15 minutes per group).

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Handouts:

It is suggested that the instructor have these sheets prepared for the students in advance to avoid line-ups at the printer. The students have access to these handouts, so if they lose their sheet or are absent that day, they can print a copy for themselves.

Part 1:

Guided reading (document) / Guided reading (pdf)

Review questions (document) / Review questions (pdf)

Part 2:

Snell's Law (document) / Snell's Law (pdf)

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Rubrics:

Part 2:

Snell's Law (document) / Snell's Law (pdf)

Part 3:

Uses of Refraction (document) / Uses of Refraction (pdf)

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Web sites:
(Here is a complete list of all the web sites used so that you can check to ensure that they are still active)

Part 1:

Readings from Physics Classroom web site

Part 2:

On-Line Simulation :  Refraction and Total Internal Reflection

Part 3:

Diamond Cutting:

Fibre Optics:

Binoculars and Periscopes:

Mirage:

 

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