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 - Light Reflection

• Objectives:
  • Define reflection
  • State the law of reflection
  • Draw ray diagrams of light reflection
  • Explain how reflection allows us to see objects
  • Predict the angle of incidence from the angle of reflection

Keywords

• Reflection
• Incident ray
• Reflected ray
• Angle of incidence
• Angle of reflection

Starter Activity

• Use a flashlight or laser pointer and a mirror to demonstrate how light reflects off a surface. Observe how light behaves when it hits a shiny surface.

Reflection

• Reflection is the bouncing of light off a surface (e.g., a mirror).
• Luminous objects emit their own light (e.g., a flame, bulb, firefly).
• Non-luminous objects do not emit light; they reflect light from a source (e.g., a ball, moon, tree).

Luminous and Non-Luminous Objects

• Luminous: Firefly, bulb, torch, fire, sun, stars
• Non-luminous: Ball, moon, earth, tree, cloth, house

Direction of Light

• Light waves travel from their source in all directions.
• When a light wave hits an object, the light wave may change direction.
• Light travels in a straight line until it hits a surface (light ray).

Group Discussion

• Light rays did not enter the observer's eyes, so they could not see the torch.

How Do We See Objects

• Light from a source (like the sun) falls on an object.
• The object reflects light in all directions.
• The reflected light reaches our eyes.
• Our brain receives the information from our eyes and allows us to see the object.

Checking Understanding

• Describe how you can see any object in your classroom.

Law of Reflection

• The angle of incidence equals the angle of reflection when a ray of light reflects off a surface.

Independent Activity

• Find the angle of reflection.

Check Your Understanding

• Calculate angle I and angle r.

Peer Assessment

• If the angle of incidence is 20 degrees, the angle of reflection is 20 degrees.
• If the angle of incidence is 45 degrees, the angle between the incident ray and reflecting surface is 45 degrees.

Day 2 - 3 - 4

• Day 2: Parent-teacher conference (early dismissal)
• Day 3: Assessment 2
• Day 4: Project: Identifying Waste Issues in the School. Conduct a waste audit, categorizing types of waste and recording their amounts.

Explore the fundamental concepts of light reflection in this quiz. You'll learn about the law of reflection, how to draw ray diagrams, and the significance of reflection in visual perception. Test your understanding of angles and how light interacts with different surfaces.