slide unit 6 light
TRANSCRIPT
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.