Light
Why can you see
lightning before you can
hear the thunder? If you could travel at the
speed of light, you could go
____________________________ around the Earth ________
times in one second.
____________________________
____________________________
Is the pencil broken?
Why is the word ambulance
written backwards?
______________________
______________________
______________________
________________________
________________________ The acronym CMYK is used to
represent the four basic colours
________________________ used for printing colour images.
What does each letter stand for?
________________________
___________
Topics we will be covering:
___________
• ___________________
___________
• ___________________
• ___________________ You will need to bring a sharp
• ___________________ pencil, rubber, protractor, ruler,
calculator and pens to every
• __________________ class.
, Light
We need light to see. Light is emitted by hot objects. It is a
form of radiation called electromagnetic radiation. Most of
our light comes from the sun which is 150 000 000 km away.
Light travels at a speed of 300 000 000 metres per second (3 x 108 m/s).
It takes 8 minutes for light from the sun to travel to us. Light from the next
nearest star takes more than 4 years to reach us.
Light travels in straight lines. A shadow is
made when an object blocks light, in which
the object is opaque or translucent.
___ light ___ light ___ light
passes passes passes Objects which transmit
through through through light are called transparent;
objects that stop light are
opaque. Some objects let
small amounts of light
through and are called
translucent.
Transparent Translucent Opaque
Complete the table by adding
some objects that are
transparent, translucent or
opaque.
Light rays are drawn on a diagram as a
straight line (use a ruler) with an
arrow to show the direction in which
the light is travelling. In the space
provided, draw 3 light rays that are
parallel.
, How Do We See Objects?
For us to see any object, light from the object must enter our eyes.
There are two ways you see objects:
1. Some objects are sources of light. We say that these objects emit light.
They are called luminous objects.
2. Other objects reflect light. They are called non-luminous objects and if
light is shining on them they are described as illuminated.
Seeing a Luminous Object
Examples of
luminous objects:
Light from the luminous
object travels in straight
lines from the object
into our eyes.
This topic Why can everyone in
introduces a lot of the room see the light
new terminology. bulb?
Note any new
words in the box
below and make Seeing a Non-luminous Object
Examples of non-
sure that you
luminous objects:
understand their
meaning:
New terminology:
Light from the light source strikes the book and
some of the light is reflected into our eyes.
Why can you see
lightning before you can
hear the thunder? If you could travel at the
speed of light, you could go
____________________________ around the Earth ________
times in one second.
____________________________
____________________________
Is the pencil broken?
Why is the word ambulance
written backwards?
______________________
______________________
______________________
________________________
________________________ The acronym CMYK is used to
represent the four basic colours
________________________ used for printing colour images.
What does each letter stand for?
________________________
___________
Topics we will be covering:
___________
• ___________________
___________
• ___________________
• ___________________ You will need to bring a sharp
• ___________________ pencil, rubber, protractor, ruler,
calculator and pens to every
• __________________ class.
, Light
We need light to see. Light is emitted by hot objects. It is a
form of radiation called electromagnetic radiation. Most of
our light comes from the sun which is 150 000 000 km away.
Light travels at a speed of 300 000 000 metres per second (3 x 108 m/s).
It takes 8 minutes for light from the sun to travel to us. Light from the next
nearest star takes more than 4 years to reach us.
Light travels in straight lines. A shadow is
made when an object blocks light, in which
the object is opaque or translucent.
___ light ___ light ___ light
passes passes passes Objects which transmit
through through through light are called transparent;
objects that stop light are
opaque. Some objects let
small amounts of light
through and are called
translucent.
Transparent Translucent Opaque
Complete the table by adding
some objects that are
transparent, translucent or
opaque.
Light rays are drawn on a diagram as a
straight line (use a ruler) with an
arrow to show the direction in which
the light is travelling. In the space
provided, draw 3 light rays that are
parallel.
, How Do We See Objects?
For us to see any object, light from the object must enter our eyes.
There are two ways you see objects:
1. Some objects are sources of light. We say that these objects emit light.
They are called luminous objects.
2. Other objects reflect light. They are called non-luminous objects and if
light is shining on them they are described as illuminated.
Seeing a Luminous Object
Examples of
luminous objects:
Light from the luminous
object travels in straight
lines from the object
into our eyes.
This topic Why can everyone in
introduces a lot of the room see the light
new terminology. bulb?
Note any new
words in the box
below and make Seeing a Non-luminous Object
Examples of non-
sure that you
luminous objects:
understand their
meaning:
New terminology:
Light from the light source strikes the book and
some of the light is reflected into our eyes.
