This chapter concentrates on the visible irradiate spectrum and how us see and also interpret light. The ideas of absorption, reflection and refraction that light will certainly be covered. Few of these ideas were very first introduced in Gr 7 power and readjust when talking about heat (the move of energy). This additionally links come what learners would have covered in Gr 7 planet Earth and Beyond top top solar energy, the seasons and life on Earth.

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4.1 Radiation of irradiate (1 hour)

Tasks

Skills

Recommendation

Activity: making a pinhole camera

Following instructions, observing, describing

CAPS suggested

4.2 Spectrum of visible irradiate (1 hour)

Tasks

Skills

Recommendation

Activity: splitting white light

Following instructions, observing, describing, explaining

CAPS suggested

Activity: colour spinning wheels

Follow instructions, measuring, observing, describing

Optional

4.3 Opaque and also transparent objects (1 hour)

Tasks

Skills

Recommendation

Activity: zero play

Following instructions, observing, describing, comparing, eplaining

CAPS suggested

4.4 absorption of irradiate (1 hour)

Tasks

Skills

Recommendation

Activity: Why perform objects watch red under red light?

Observing, explaining

Suggested

4.5 reflection of irradiate (2 hours)

Tasks

Skills

Recommendation

Investigation: Is over there a relationship between the angles of incidence and also reflection?

Investigating, comparing, measuring, observing, describing, explaining

CAPS suggested

Activity: light reflection off aluminium foil

Comparing, observing, describing, explaining

CAPS suggested

4.6 Seeing light (1 hour)

Tasks

Skills

Recommendation

Activity: see colours

Interpreting, drawing

CAPS suggested

4.7 Refraction of irradiate (2 hours)

Tasks

Skills

Recommendation

Investigation: does light adjust direction once it passes through a glass block?

Investigating, comparing, measuring, analysing, describing, explaining

CAPS suggested

Activity: Magic coin trick

Observing, describing, explaining

Suggested

Activity: Diverging and also converging light with lenses

Observing, describing, comparing, explaining

CAPS suggested

Activity: research careers in optics

Researching, working in groups, writing

Optional

Note: second investigation has been had only in the Teacher"s overview in this section:

Investigation: The refraction of light as it enters water (PhET simulation) This have the right to be perform if you have an internet connection and also is an alternate to the argued investigation above.


whereby does irradiate come from? how does irradiate travel? how do we see? Why do leaves watch green? how do mirrors work? Why execute my legs look crooked underwater?
In this thing we will certainly learn about visible light. We speak to it clearly shows light because we deserve to see it with our own eyes. Over there are different forms of irradiate which we cannot see with our nude eyes. Ultraviolet light is an example of a kind of irradiate which us cannot view with just our eyes. We will emphasis our fist on the visible irradiate spectrum and investigate how we space able to see various colours and how light behaves.


Where does irradiate come from? natural light originates from luminous objects such as the Sun and light bulbs. We say the these objects emit light.


The Moon is not a luminous object as it does not emit its very own light light. It shows the irradiate from the Sun.


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The sun is our main source of light on Earth.
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A light pear is a luminous object as it emits light.
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This photo from NASA reflects the Earth"s lights at night. You have the right to see exactly how much we count on light nowadays.

If you might travel in ~ the rate of light you can travel around the equator 7,5 time in 1 second!


Light travel through space at a rate of 300 000 kilometers every second. We say that energy is moved by radiation. The energy of the light is transferred through room as electromagnetic waves in right lines.

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Light and heat are transferred to earth through room from the sun by radiation.

The sun emits radiation inall directions, yet in the chart here, only the radiation i beg your pardon reaches earth has to be shown.


an exciting method to introduce this ar is to rotate your classroom right into a camera obscura. Use black document to cover all the windows and also tape to block out any type of light coming in indigenous under any type of doors. ~ above one window, leave a little area that the home window uncovered. Hang a white paper in the center of the room opposite come the exposed window. The check out from external should be projected top top the sheet. The photo will it is in upside down. This is an inexpensive way to provide the learners an possibility to know the rectilinear propagation that light.


This task allows the learners to produce images ~ above a screen. The images developed by a pinhole camera have the right to be offered to explain and also demonstrate the light travels in right lines.

The Pringles chip have the right to is the perfect form for this activity. You could use any kind of cardboard tube. Rather of the lid from the Pringles can you can use a piece of wax paper as the screen. This pinhole camera is basically a miniature camera obscura.

If you are struggling v time, you can make one of these and also demonstrate it to the learners instead of having actually each learner develop one.


girlfriend can likewise use black document if you perform not have aluminium foil. The foil is useful due to the fact that it molds to the shape of the tube and helps protect against ambient irradiate from entering.


INSTRUCTIONS:

measure 5 centimeter from the bottom of the deserve to (opposite finish to the plastic lid) and make a mark all about the can.

Cut v the deserve to along the line so the you have reduced the have the right to into 2 pieces.

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If you have actually a clean lid, put a piece of wax paper on height of the lid prior to sticking whatever together.

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Place the lid in between the 2 pieces and stick it all together using tape.

See more: What Is A Sling Psychrometer Used To Measure ? What Is A Sling Psychrometer Unit Of Measurement

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Wrap the aluminium foil around the have the right to to prevent any light from coming in indigenous the sides.

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use a drawing pin to make a feet in the centre of the steel base of the can. Go external with her pinhole camera. Allude the metal finish with the hole at an object which is in glowing sunlight. Cup her hands about the other end and look v the open up end.

QUESTIONS: