Transcript NEXT MATERIAL Light In this unit: 1) 2) 3) 4) Properties of light Colours Mirror Lens A – Properties of Light 1.

NEXT
MATERIAL
Light
In this unit:
1)
2)
3)
4)
Properties of light
Colours
Mirror
Lens
A – Properties of Light
1. Light travels in straight lines:
Laser
Shadows
Shadows are places where light is “blocked”:
Rays of light
2. Light travels VERY FAST –
around 300,000 kilometres per
second.
At this speed it can
go around the world 8
times in one second.
Light travels much faster than sound (340 m/s).
For example:
1) Thunder and lightning
start at the same time,
but we will see the
lightning first.
2) When a starting pistol
is fired we see the light
first and then hear the
bang.
3. Can be Reflected
How to be
Succes
We see things because they
reflect light into our eyes:
Homework
4. Can be Refracted
5. Dispersion
Colour
White light is not a single colour; it is made
up of a mixture of the seven colours of the
rainbow.
We can demonstrate this by
splitting white light with a
prism:
This is how rainbows are
formed: sunlight is “split up”
by raindrops.
6. Merambat di Ruang Hampa
(Electromagnetical Wave)
7. Have Energy
• Solar Cell
Properties of Light summary
Properties of Light
(Ringkasan)
Merambat lurus, dipantulkan
Dibias, diurai 7 warna
Merambat cepat, dibelokkan
Diserap, menembus benda bening
Dilihat, hampa, daan.. memiliki energi
Interferensikan juga dipolarisasikan
Cahaya mantul pasti kembali
Seumpama ada dua buah benda bening
Membias!
Can be Reflected
How to be
Succes
Law of Reflection
Reflection from a mirror:
Normal
Reflected ray
Incident ray
Angle of
incidence
Angle of
reflection
Mirror
The Law of Reflection
Angle of incidence = Angle of reflection
The
same !!!
Clear vs. Diffuse Reflection
Smooth, shiny surfaces
have a clear reflection:
Rough, dull surfaces have
a diffuse reflection.
Diffuse reflection is when
light is scattered in
different directions
Using mirrors
Two examples:
2) A car headlight
1) A periscope
Flat Mirror
1.
2.
3.
4.
Size :
Left-right:
Up-down:
Virtual (unreal) :
phenomena
Phenomena-2
Experiment
What do you think
This student floating on the air....?
This one...
How about this one...?
Or this one...?
I don’t know about this
How many baby/babies..?
Wich is the real one..?