To describe reflection
Science - Light and Sound
Dr Heckmann
Key principles
The I do phase involves the explanation - indicates where a teacher would be explaining and modelling a concept.
Moving from I do to We do involves guided practice - moving from teacher-led instruction to student-led practice.
Check for Understanding - Formative instruction questions, posed to check whether students have understood and to inform next instructional steps.
You do - Practice - indicates places where students will attempt questions independently.
At the expected level for the lesson; all students should be able to do these questions.
A small increase in difficulty from the expected level, eg larger numbers or a more complex calculation.
Extension - increased difficulty; suitable for a small number of students.
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I
CfU
W
Y
Support - support materials, such as additional templates or questions with fewer steps.
Engagement icons - to go in top right corner
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Whiteboard response
All students respond to the teacher’s question, showing their responses at the same time.
Non-volunteers
The teacher asks a question, gives wait time, then calls on individual students to respond.
Written response
Students respond to a prompt in a template, their exercise book or booklet.
Pair share
Students discuss with the person next to them.
Choral response
Students respond orally all together.
Thumbs up, thumbs down
Students indicate whether they agree or disagree with a statement, or whether something is an example or non-example.
Concrete materials
Teacher might choose to illustrate this teaching point using concrete materials.
Class discussion or activity
Students discuss as a class and share ideas
Calculator
Students will need a calculator to perform the task on this slide.
Spreadsheet
Students will need access to spreadsheet software to perform the task on this slide.
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Exercise book or paper
Pencil
Image credit: Pixabay
In this lesson, you will need:
Ruler
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Starter quiz
Recap previous lessons
Reflection, transmission, absorption
Ray diagrams and the Law of Reflection
Exit quiz
Keywords
Reflection (of light): The return of light waves after hitting a surface
Luminous: Objects that make their own light.
Opaque: Not able to be seen through.
Translucent: Allowing some light to pass through but no clear image is produced.
Transparent: Allowing light to pass through so that objects behind can be seen clearly.
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Lesson recap: What is light?
What we learnt so far
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Reflection, transmission, absorption
How does light interact with objects - Reflection
Take a moment and write down things that produce light.
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Credit: Pixabay
How does light interact with objects - Absorption
Absorption is the transfer of light energy into an object where it is transferred into heat energy.
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Credit: Pixabay
How does light interact with objects - Transmission
Transmission is when light passes through an object without being absorbed or reflected.
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Credit: Pixabay
Task 1: How does light interact with objects?
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To describe reflection worksheet
Complete task 1 in the worksheet.
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Properties of objects
Objects can be transparent, translucent, or opaque depending on how much light can pass through the object.
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Credit: Pixabay
Transparent | Translucent | Opaque |
Almost all light passes through | Some light passes through | No light passes through |
You see a clear image through it | You see a blurred image through it | You cannot see through it |
Task 1: How does light interact with objects?
Match each diagram to the type of interaction of light with the object.
reflection
absorption
transmission
bending of light when it bounces off a surface
transfer of light energy into heat inside object
light passes through an object
Task 2: Properties of objects
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To describe reflection worksheet
Complete task 2 in the worksheet.
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Task 2: Properties of objects
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| opaque | transparent | translucent |
Explain in your own words | Light cannot pass through | Almost all light passes through | Some light passes through |
Can you see through the object? | No | Yes (clear image) | Yes (blurry image) |
Example | E.g. apple | E.g. window | E.g. ice |
Copy the table below in your exercise book and complete it.
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Ray diagrams and the Law of Reflection
The “normal”
Before we learn more about reflection we need to learn about the “normal”.
The “normal” is a line perpendicular (at 90° degrees) to a surface.
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Find the “normal”
Copy the surfaces below in your exercise book (tip: you can draw them as a line). Draw the normal line for each of them.
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The law of reflection
On reflection from a smooth surface, the angle of the reflected ray is equal to the angle of the incident (incoming) ray.
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Angle of incidence
Angle of reflection
The law of reflection
On reflection from a smooth surface, the angle of the reflected ray is equal to the angle of the incident (incoming) ray.
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Credit: PHET
Task 3: Law of reflection
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To describe reflection worksheet
Complete task 3 in the worksheet.
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Task 3: Law of reflection
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Angle of incidence | 10° | 45° | 70° |
Angle of reflection | 10° | 45° | 70° |
Reflection of light on different surfaces
How light is reflected depends on the type of surface the object has.
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Credit: Pixabay
Reflection of light on different surfaces
Remember: Light travels as rays in a straight line.
We can draw ray diagrams to show how light is reflected on a surface.
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Task 4: Ray diagrams
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To describe reflection worksheet
Complete task 4 in the worksheet.
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Task 4: Ray diagrams
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Smooth surface
regular reflection
Rough surface
diffuse reflection
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Starter quiz
Recap previous lessons
Reflection, transmission, absorption
Law of reflection
Exit quiz
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