Waves and Their Applications: Unit 1 - Module L

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 diagram
  • 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.
• Light reflects in a uniform/single direction.
• Examples: mirrors, polished metals, calm water, CDs, DVDs

Diffused Reflection

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

Starter Activity

• What is the difference between the two pictures shown? (Illustrative pictures showing regular vs. diffuse reflection)

Refraction

• Light travels through a medium.
• Light slows down and bends.
• The bending of light as it passes from one medium to another is called refraction.
• The prism bends light.

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

• Component C on diagram
• Component D on diagram

Day 2 - Light Refraction

• Objectives:
  • Draw and label refraction diagram
  • Define denser and rarer medium
  • Explain how light travels 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 (Day 2)

• Label the ray diagram showing refraction and reflection of light.

Previous Knowledge

• Light travels slower in denser/thicker materials (Solid > Liquid > Gas > Vacuum)

Which is denser/thicker?

• Air or glass? Answer: Glass
• Light travels slower in glass than in air.
• Light bends as it goes slower.
• Glass is optically denser (particles are closer)
• Air is optically rarer (particles are further away)

Checking Understanding

• Describe any refraction of light in your classroom. Include its speed, bend, media (denser or rarer), etc.

Summary of Light Travel from Optically Rare to Dense

• When light travels from optically rare (e.g., air) to optically denser (e.g., glass):
  • Light travels slower
  • Light bends towards the normal

Summary of Light Travel from Optically Dense to Rare

• When light travels from optically dense (e.g, glass) to optically rarer (e.g., air):
  • Light travels faster.
  • Light bends away from the normal

Think Pair Share - Check Your Understanding

• Choose the correct sketch showing the situation, the interface between media, the normal line, the incident ray, and the reflected rays.

Group Work - Practice Drawing (Peer Evaluation)

• Draw the reflected light in the diagrams below.
• Exchange papers with another group
• Evaluate each other's work using the teacher's answer key
• Post completed work.

Compare Denser And Rarer Media

• Denser media: Light travels slower, closer particles
• Rarer media: Light travels faster, further away particles

Activity - Quizizz

• Participate in a quiz related to absorption, reflection, and refraction using the provided link.

Explore the concepts of regular and diffused reflection and refraction in this quiz designed for Unit 1, Module L. Understand how waves interact with various materials through reflection, absorption, and transmission. Evaluate your knowledge with diagrams and vocabulary definitions related to the topic.