UNIT 6 :LIGHTZULIZA BINTI MAT RUSOK @ HASSAN

D20111048073

What is the difference between your shadow and your image in a mirror ?

We are grateful that God has created the Sun. Light from the Sun travels to the Earth and enables us to see things. How does light travel ?

When we stand facing away from the Sun, we see our shadows on the

ground in front of us.

WHAT IS SHADOW ? HOW DOES IT FROM?

At the end of this unit, you will learn about :

How light travels ?

How shadows are formed and the factors that cause the size and shape of a shadow to change ?

The reflection of light, ray diagram and uses of the reflection of light in everyday life.

How does Light Travel ?

Look through a rolled paper to see

object. What you see ?

You can use a torch to see things in a dark room. Look at how the light beam from

the torch.

Now, bend the paper and look through it again. Can you see the object ?

You cannot see the object through the bend rolled paper because light from the object cannot pass

through it. This shows that light travels in a straight line.

The search light from

helicopter

The ray Of the sun

The beam of light from

lighthouse

DID YOU KNOW ???Light travels at a speed

of 300 000 km per second. At this speed, light from sun reaches

the Earth within 9 minutes

Many events or phenomena show

that light travels in a straight line.

Light Travels in Straight Lines

How Shadow does formed ?

A shadow is formed when light from a light source is blocked by an opaque or translucent

Can you different sizes of shadow from the same

objects ?Let go for get

the Answer….

Size and Shape of ShadowThe size of a shadow can be changed by

changing :• Distance between the light source and

the object• Distance between the object and the

screen

Now , you know how to change the shape of a shadow ?

The shape and of a shadow can be change by :

• The position of the light source

• The position of object

Bouncing Light

When you look at mirror, you see your image in the mirror . The light from a light source

falls on you. This light is reflected into the mirror and the mirror reflects the image

into your eyes

The reflection of light can be shown in the form of a

ray diagram.

We can see light around us because light from a source is reflected by object

.

Reflection of light is very important in everyday life

Some objects reflect light better than others. Mirrors

and aluminium foils are good reflectors of light because their surfaces are smooth

and shiny

Some of the example are shown :

Periscope Dental Mirror

Convex MirrorSide Mirror

CONCLUSION :1. Light travels in a straight line.2. A shadow is formed when light is blocked by an opaque or

translucent object.3. The size of shadow changes according to :

Distance between object and light source Distance between screen and object

4. The shape of a shadow change according : The position of the light source The position of the object

5. Light can be reflected.6. We can see an object because light from a light source that falls

onto the object is reflected by object onto our eyes.