This lesson contains 20 slides, with interactive quizzes, text slides and 1 video.
Lesson duration is: 50 min
Items in this lesson
Shadow (p. 22)
Bluetooth
- On
Stationary
- Books
- Pen and pencil
- iPad
Report
- NO
Lessonup
- Yes
Bags in
the cuboard
Phones in the phone holder
Slide 1 - Slide
Lesson goals:
Explain what light rays, partial shadow and full shadow is.
Name the types of light beams and explain their uses:
Divergent light beams
parallel light beams.
Explain what a point source is.
Slide 2 - Slide
Light rays
Light rays move in straight
lines.
Light rays only become vissible when they reflect off other objects, e.g. During a lightshow, there needs to be smoke particles present in the air otherwise you dont see the laser beams.
A shadow forms when objects block light rays.
Slide 3 - Slide
Why is the sky blue?
Light form the sun is scattered
when it enters our atmosphere.
This is called diffuse light.
Blue is scattered more than
the other colours, and therefore the more prominent colour.
Slide 4 - Slide
Activity 8 (p. 30)
We do it differently
Use the fluorescent tube above you as lightsource, and your hand as an object
timer
2:00
Slide 5 - Slide
Types of shadow
Partial shadow: A shadow that
receives light from more lightsources.
Full shadow: The light from all lightsources is stopped by the lit-up object.
For work spaces sharp shadows are unpleasant. That is why they are usually equipped with fluorescent tube lighting.
Slide 6 - Slide
Slide 7 - Slide
Types of light beams
o Point source: Light comes from one place. o Divergent light beam:
Light rays spread out.
(point source) o Parallel light beam:
Licht rays dont spread out.
(laser)
Slide 8 - Slide
With a divergent light beam all light comes from one point.
A
True
B
False
Slide 9 - Quiz
With a parallel light beam the shadow is always the same size as the object.
A
True
B
False
Slide 10 - Quiz
With a divergent light beam the shadow is the same size as the object.
A
True
B
False
Slide 11 - Quiz
You can never see light rays.
A
True
B
False
Slide 12 - Quiz
Partial shadow is the area where no light reaches.
A
True
B
False
Slide 13 - Quiz
How can we see light?
A
Reflection
B
Diffusion
C
Parallel
D
Dispersion
Slide 14 - Quiz
Explain why the sky is blue.
Slide 15 - Open question
Which part of the drawing is partial shade?
A
B
C
A
A
B
B
C
C
Slide 16 - Quiz
Slide 17 - Video
What kind of light beam was used to make this presentation?
A
divergent
light beam
B
parallel
light beam
C
convergent
light beam
Slide 18 - Quiz
Do the following questions:
20 t/m 23 (blz. 24)
In your writingbook
Rules:
- 10 minutes
- No talking
Finished early: search more shadow theatre on youtube, and see what you can say about the kind of light beam they use.
timer
10:00
Slide 19 - Slide
In a nutshell:
You can only see light when it is reflected.
Shadows apear when light is blocked by objects. Partial shade forms when some light is blocked, but still other light raches the area where the shadow forms.