Reflection and
Laws of Reflection
Understanding How Light Behaves
When It Encounters a Surface
Learning Objectives
By the end of this lesson, you will be able to:
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Define and explain the concept of
reflection.
Identify and describe the two laws of
reflection.
Differentiate between regular and diffused
reflection.
Apply the laws of reflection to solve realworld problems.
Recognise the importance of reflection in
daily life and technology.
Key Vocabulary
Reflection
Normal
The bouncing back of light when it hits a
surface.
An imaginary line perpendicular to the
surface where the light ray strikes.
Incident Ray
Angle of Incidence
The light ray that strikes a surface.
The angle between the incident ray and
the normal.
Reflected Ray
The light ray that bounces off the surface
after reflection.
Angle of Reflection
The angle between the reflected ray and
the normal.
What is Reflection?
Understanding Reflection
Reflection occurs when light strikes a surface
and bounces back into the same medium. This
phenomenon allows us to see objects around
us.
Everyday Examples
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Seeing your face in a mirror.
The shine of a polished surface like a car.
The reflection of mountains in a calm
lake.
Reflection is a fundamental property of light
and is used in various applications, from
mirrors to optical devices.
Types of Reflection
Regular Reflection
Diffused Reflection
Occurs on smooth surfaces like mirrors.
The reflected rays are parallel, forming a
clear image.
Occurs on rough surfaces like walls. The
reflected rays scatter in different
directions, forming no clear image.
Laws of Reflection
First Law
Second Law
The angle of incidence is equal to the
angle of reflection. This means the light
bounces off at the same angle it strikes
the surface.
The incident ray, the normal, and the
reflected ray all lie in the same plane. This
ensures the light's path is predictable and
consistent.
Real-World Applications
Mirrors
Periscopes
Used in homes, vehicles,
and telescopes to reflect
images.
Used in submarines to see
above the surface of water
by reflecting light.
Optical
Instruments
Devices like cameras and
microscopes use
reflection to focus light
and form images.
Practice and Application
Activity: Predicting Reflections
1. Draw a straight line to represent a mirror.
2. Draw an incident ray hitting the mirror at
a specific angle.
3. Use the laws of reflection to draw the
reflected ray.
4. Label the angles of incidence and
reflection.
Real-Life Question
Why do you see a clear reflection in still water
but not in turbulent water? Use the concepts of
regular and diffused reflection to explain.
Reflection in Technology
Solar Panels
Traffic Mirrors
Use reflection and refraction to maximise
sunlight absorption for energy.
Placed at blind spots to reflect a wider
field of view for drivers.
Summary
Key Takeaways
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Reflection is the bouncing back of light
when it encounters a surface.
The two laws of reflection govern how light
behaves during reflection.
Regular and diffused reflection depend on
the smoothness of the surface.
Reflection has practical applications in
mirrors, optical devices, and technology.
Understanding reflection helps us appreciate
its role in both nature and human innovation.