Waves and Their Applications - Reflection and Refraction

Waves and Their Applications

• Unit 1 - Module L
• Standard MS-PS4-2: Develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials.

Day 1 - Regular & Diffused Reflection/Refraction

• Objectives:
  • Define regular and diffused reflection
  • Define refraction
  • Label reflected and refracted ray diagrams
  • Explain how refraction takes place
  • Compare regular and diffused reflection
• Vocabulary:
  • Refraction
  • Angle of incident
  • Angle of refraction
  • Diffused
  • Regular

Regular Reflection

• Light bounces off a smooth surface and reflects in a uniform/single direction.
• Examples: mirrors, polished metals, calm water, CDs, DVDs

Diffused Reflection

• Light bounces off a rough surface and reflects in different/multiple directions.
• Examples: walls, wood, irregular objects (bags, books, papers, people)

Starter Activity

• What is the difference between the provided pictures? (Two diagrams showing light reflection)

Refraction

• Light changes direction as it passes from one medium to another.
• Matter can refract light

From the Video About Refraction:

• What bends light that passes through the prism? (The prism bends light)
• What is refraction? (Change in direction of light as it passes from one medium to another)

Labeling Parts of Refraction Diagram

• Incident ray
• Normal
• Angle of incidence
• Boundary
• Substance 1
• Substance 2
• Angle of refraction
• Refracted ray

Label C and D

• C - Incident ray
• D - Refracted ray

Day 2 - Light Refraction

• Objectives:
  • Draw and label refraction diagrams
  • Define denser and rarer medium
  • Explain how light travels as it passes from a rarer medium to a denser medium, and vice versa
  • Compare and contrast denser and rarer medium
• Vocabulary:
  • Rarer media
  • Denser media

Starter activity:

• Label the ray diagram to show refraction and reflection of light. (Diagram is provided)

Previous Knowledge:

• Light travels slower in denser/thicker materials (solid > liquid > gas > vacuum)

Comparing Denser and Rarer Media:

• Denser media: Light travels slowly, particles are closer together
• Rarer media: Light travels faster, particles are further apart.

Checking Understanding:

• Describe any refraction of light seen in your classroom. (Describe speed, bends, denser/rarer medium)

When Light Travels From...

• Optically rare to optically denser (slower): Light bends towards the normal (e.g., from air to glass)
• Optically denser to optically rarer (faster): Light bends away from the normal (e.g., from glass to air)

Think Pair Share Check Your Understanding (Activity)

• Choose the correct sketch of the refractive situation between the media (interface, normal line, incident ray, reflected rays to the right) Three diagrams are provided

Group Work (Peer Evaluation)

• Draw the reflected light in diagrams below.
• Exchange your paper with another group.
• Evaluate each other's work by the teacher's answer key
• Post your work on the bulletin board (There are diagrams given as examples)

Activity - Quizizz:

• (Link to quizizz) https://quizizz.com/admin/quiz/61702152c37755001d0501c8/ab-sorption-reflection-refraction

Explore the principles of regular and diffused reflection and how refraction occurs. This quiz will assess your understanding of wave behavior as it moves through various materials. Get ready to label ray diagrams and compare different types of reflection!