Page 2 - Lesson Notes- Types of object and rectilinear propagation

Interactive Activities

1. Shadow Fun with Opaque, Transparent, and Translucent Objects
Materials: Torch, white wall/screen, objects (glass, butter paper, book)
Steps:
• Shine the torch on each object and observe the type of shadow
formed.
• Transparent → no shadow
Translucent → faint shadow
Opaque → dark, sharp shadow

2. Create a Light Maze
Materials: Torch, mirrors, cardboard
Steps:
• Set up mirrors in a zigzag pattern.
• Try to bounce light from the torch to hit a target.
• Adjust angles and observe reflection.

Real-Life Applications of Light & Its Properties
Rectilinear Propagation of Light
• Cameras: Form clear images using straight light paths.
• Projectors: Project images in straight beams onto a
screen.

Transparent Materials
Laboratory glassware: Scientists observe reactions through transparent beakers/test
tubes.
Translucent Materials
Frosted window glass: Maintains privacy while letting some light in.
Opaque Materials
Walls and curtains: Block light completely to create dark spaces.

Concept Extension (For curious minds)
Can Light Bend?
• Although light usually travels in straight lines, it can bend when it
moves from one material to another—this is called refraction.
Light Can Be Trapped!
• In optical fibres, light bounces inside in straight lines but
doesn’t escape.
• This is how internet signals and surgeries work using light—
total internal reflection!