This chapter focuses on the visible light spectrum and also how we see and also interpret light. The principles of absorption, reflection and also refraction of light will certainly be covered. Few of these principles were an initial introduced in Gr 7 energy and change when talking around heat (the carry of energy). This additionally links come what learner would have covered in Gr 7 world Earth and also Beyond ~ above solar energy, the seasons and also life on Earth.

You are watching: When light passes through an object

4.1 Radiation of light (1 hour)

Tasks

Skills

Recommendation

Activity: make a pinhole camera

Following instructions, observing, describing

CAPS suggested

4.2 Spectrum that visible irradiate (1 hour)

Tasks

Skills

Recommendation

Activity: splitting white light

Following instructions, observing, describing, explaining

CAPS suggested

Activity: color spinning wheels

Follow instructions, measuring, observing, describing

Optional

4.3 Opaque and transparent objects (1 hour)

Tasks

Skills

Recommendation

Activity: shadow play

Following instructions, observing, describing, comparing, eplaining

CAPS suggested

4.4 absorption of irradiate (1 hour)

Tasks

Skills

Recommendation

Activity: Why perform objects look red under red light?

Observing, explaining

Suggested

4.5 have fun of irradiate (2 hours)

Tasks

Skills

Recommendation

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

Investigating, comparing, measuring, observing, describing, explaining

CAPS suggested

Activity: irradiate reflection turn off aluminium foil

Comparing, observing, describing, explaining

CAPS suggested

4.6 Seeing irradiate (1 hour)

Tasks

Skills

Recommendation

Activity: see colours

Interpreting, drawing

CAPS suggested

4.7 Refraction of light (2 hours)

Tasks

Skills

Recommendation

Investigation: go light readjust direction when it passes v 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 v lenses

Observing, describing, comparing, explaining

CAPS suggested

Activity: research careers in optics

Researching, working in groups, writing

Optional

Note: second investigation has been consisted of only in the Teacher"s guide in this section:

Investigation: The refraction that light together it start water (PhET simulation) This deserve to be carry out if you have an net connection and also is an alternate to the said investigation above.


wherein does light come from? exactly how does light travel? just how do us see? Why carry out leaves watch green? just how do mirrors work? Why do my foot look crooked underwater?
In this chapter we will certainly learn around visible light. We contact it visible light due to the fact that we have the right to see it through our own eyes. Over there are different forms of light which us cannot see with our nude eyes. Ultraviolet irradiate is an example of a type of light which we cannot watch with just our eyes. We will emphasis our attention on the visible irradiate spectrum and investigate how we space able to see various colours and also how irradiate behaves.


Where does irradiate come from? herbal light comes from luminous objects such as the Sun and light bulbs. Us say that these objects emit light.


The Moon is no a luminous object as it does no emit its very own light light. It mirrors the irradiate from the Sun.


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The sun is ours main resource of light on Earth.
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A light bulb is a luminous object together it emits light.
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This picture from NASA shows the Earth"s lights at night. You can see how much we depend on light nowadays.

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


Light travels through an are at a rate of 300 000 kilometers per second. We say that energy is transferred by radiation. The power of the light is moved through space as electromagnetic waves in right lines.

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Light and heat room transferred to earth through space from the sunlight by radiation.

The sun emits radiation inall directions, yet in the diagram here, only the radiation which reaches earth has been shown.


one exciting way to introduce this section is to revolve your classroom right into a camera obscura. Usage black record to cover every the windows and tape come block out any light comes in from under any type of doors. ~ above one window, leave a tiny area the the home window uncovered. Hang a white paper in the center of the room opposite come the exposed window. The see from external should be projected ~ above the sheet. The photo will it is in upside down. This is an inexpensive method to give the learners an opportunity to recognize the rectilinear propagation the light.


This task allows the learner to develop images top top a screen. The images developed by a pinhole camera have the right to be used to explain and also demonstrate that light travels in straight lines.

The Pringles chip deserve to is the perfect shape for this activity. You might use any type of cardboard tube. Rather of the lid from the Pringles have the right to you deserve to use a item of wax paper as the screen. This pinhole camera is essentially a miniature camera obscura.

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


you can also use black document if you carry out not have aluminium foil. The silver paper is useful due to the fact that it molds come the form of the tube and also helps avoid ambient light from entering.


INSTRUCTIONS:

measure up 5 cm from the bottom of the can (opposite end to the plastic lid) and also make a note all about the can.

Cut through the have the right to along the heat so the you have reduced the can into 2 pieces.

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If you have a clean lid, placed a piece of wax record on optimal of the lid before sticking everything together.

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Place the lid in between the 2 pieces and also stick it all with each other using tape.

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Wrap the aluminium foil about the can to prevent any type of light from coming in native the sides.

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use a drawing pin to make a hole in the centre of the steel base of the can. Go exterior with your pinhole camera. Point the metal finish with the hole at things which is in glowing sunlight. Cup your hands about the various other end and also look with the open end.

QUESTIONS: