LabLearner—The Science of Learning
LabLearner—The Science of Learning

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Investigation 4 – PreLab

 

 

 

 

 

 

 

Back to Investigation 4

ZERO-IN

Italicized font represents information to be shared orally or physically completed with the students at this time.

The non-italicized font represents additional information included to support the teacher’s understanding of the content being introduced within the CELL.

ASK WHY

Remind students that light is all around us. It has the ability to tan or burn our skin. It can be harnessed to melt metals, create electricity, and heat our food. It gives us sight, color, warmth, and enables gadgets like computers, cameras, televisions, traffic lights, mirrors, eyeglasses, and microscopes to function.

BRANCH OUT

Remind students that optical engineers work in all areas of optics, using different techniques to design lasers, build telescopes, create fiber optics communication systems, and much more.

GET FOCUSED

Inform students that the Investigation is designed to help them to answer the following Focus Question:

  • How does a change in mediums affect the wavelength of light? When light passes from one medium to another, the speed of the wavelengths change. This causes the light wave to change directions. This process is called refraction.

Note: This question is located in students’ SDRs at the beginning and end of the Investigation.

Note: This is a succinct response to the Focus Question and is placed here for your reference at this time. Fully developed responses to the Focus Questions can be found on the PostLab page.

GO DEEPER

As a class, read the Background(s) in the Investigation. Have students read the information aloud or silently to themselves. When students have finished, discuss the following concepts as a class:

  • The refraction of light occurs whenever light travels from one medium to another.
  • Because light waves travel at different speeds through different mediums, the light waves are bent as they move from one medium to another. For example, light travels at 290,000,000 m/s in the air but slows down to 225, 000,000 m/s in water. The lightwave slows as it enters the water, and bends or refracts. As a result, if we were to view an object at the bottom of a pool or lake through the water, it would appear different than if it were viewed in air, outside of the water.
  • The angle at which the light wave enters the water is called the angle of incidence.
  • The angle at which the light wave is refracted in the water is called the angle of refraction.
  • Different transparent mediums or substances refract or bend light to different degrees.
  • A measure of the degree to which a medium refracts light is indicated by a value called the index of refraction.
  • The index of refraction of air is 1.00.

Note: These concepts are integrated into the Background(s) and are used to deepen students’ comprehension of the big ideas.

 

LEARN THE LabLearner LINGO

The following list includes Key Terms that are introduced in the Investigation Background(s). They should be used, as appropriate, by teachers and students during everyday classroom discourse.

  • refraction
  • index of refraction

Note: Definitions of these terms can be found on the Introduction page to the CELL.

Note: Additional words may be bolded within the Background(s). These words are not Key Terms and are strictly emphasized for exposure at this time.

SET FOR SUCCESS

  • Review the three ways in which light can interact with a medium, transmission, absorption, and reflection. Elicit student descriptions of each as well as short descriptors of how each relates to the perception of color.
  • Ask students to summarize how they investigated the behavior of light thus far.
  • Explain that students will investigate a fourth way in which light can interact with a medium, refraction.
  • Ask students to reflect on what they have learned about refraction thus far then direct them to complete the Apply section in their SDRs. Student answers may vary.
  • Can you think of an everyday life application of this property of light?
  • What might you observe as an example of refraction?
  • Play the video below. Stop to ask students questions or answer students’ questions when necessary. Remind students to follow along with their SDRs and make any notes that they think might be helpful.
  • After the video, direct students to divide into their lab groups to discuss their strategy for the lab. For example, they may assign certain group members to perform specific functions during the lab.

Note: The purpose of the video is to allow students to anticipate the laboratory experience they will soon encounter. Students should leave this PreLab session with a firm idea of what to expect and how to perform in the lab.

Note: Homework is posted below the video.

HOMEWORK

Tell students that they should review the Investigation in preparation for the Lab.