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light and shadow - Coggle Diagram
light and shadow
how light help us see things
objects that cannot give off light of their own
they must reflect light form a source of light
to enter our eyes so that we can see them
e.g.
we cannot see a table and chair in the dark
but when we turn on the lamp
we can see the table and chairs in the room as
they reflected light from the lamp into our eyes
reflection of light helps us to see
images of object in the mirror
light from the surroundings is reflected by object
first onto the smooth surface of the mirror
the light is than reflected again by the smooth surface of the mirror
and enters our eyes
this enables us to see images of object in the mirror
when an object is a light source
it can give off light that can enter our eyes
so we can see the object directly
a periscope make use of mirrors arranging
in certain ways to enable us to
see objects that are out of sight
e.g
around the corners of a street
light from the object can enter our eye
in one of the following ways
an object is a source of light
an object reflect light
from a source of light
this is how a periscope helps us to see things that
are out of sight
the object reflect the light from the surroundings
onto the first mirror
the first mirror reflect the light onto second mirror
the second mirror the reflect the light into our eyes
for us to see the object
we can see object in our surroundings
when light from these objects enter our eyes
how light pass through different materials
e.g. of transparent, translucent and opaque
transparent
glass
air
clear plastic
translucent
frosted glass
tracing paper
cloth
opaque
metal
wood
clay
the thickness of the material
affect the amount of light passing through it
the thicker the material
the lesser the amount of light can pass through
there are 3 main groups of materials that allow
different amount of light to pass through them
translucent
allows some light to pass through
and we cannot see through it clearly
opaque
does not allow light to pass through
and we cannot see through it
transparent
allows mot light to pass through
and we can see through it clearly
not all materials allow the same amount of light
to pass through them
when conducting an experiment
to find out the amount of light
passing through an object
the experiment should be conducted in dark place
this is to ensure that no other light sources
from the surroundings are detected by the light sensor
so that accurate results can be obtained
a light sensor connected to a data logger
can be used to measure the amount of light
that passes through an object or place
how shadows are formed
not all objects can produce a clear shadow
only objects m
the characteristic of shadow
shadows always form on the opposite
of the light source
the shape of the shadows
are similar to the shape of the objects
light travels in straight lines
when light is blocked by an object
shadows are formed
introduction of light
light help us see things
in our surroundings
light travels in straight lines
light is a form of energy
sources of light
the sources of light are any object
that can give off light of their own
e.g of sources of light in our surroundings
sun
stars
animals such as
fireflies
fuels when they burn such as
firewood
coal
some non living things when
they are switched on such as
lamp
torchlight
electric bulb
way to change the shape/size of shadow