Download 11.4 Ray Model of Light

11.4 Ray Model of Light
Remember...
Light travels in straight lines
YOU WILL NEVER SEE A FLASHLIGHT BEAM GO AROUND A CORNER!
A candle radiates light in all
directions
A LIGHT RAY is a
line on a diagram
representing the
direction and path
that light is
traveling.
Incident Light:
light emitted from a source that
strikes an object
•
Matter can be classified into three categories
depending on how it behaves when light strikes it
Term
Transmission
of Incident
Light
Transparent All light
transmitted
Clarity of Object
through material
Example
The Ray Model of Light
Translucent
Some light
transmitted,
some absorbed
or reflected
Opaque
No light
transmitted, all
absorbed or
reflected
Term
Transmission
of Incident
Light
Clarity of Object Example
through material
Transparent All light
transmitted
Object is seen
clearly
Translucent
Some light
transmitted,
some absorbed
or reflected
Object is seen, but
not clearly
No light
transmitted, all
absorbed or
reflected
Object is not seen
at all
The Ray Model of Light
Opaque
Term
Transmission
of Incident
Light
Clarity of Object
through
material
Example
Transparent All light
transmitted
Object is seen
clearly
Clear
glass
Translucent
Some light
transmitted,
some absorbed
or reflected
Object is seen, but Frosted
not clearly
glass
Opaque
No light
transmitted, all
absorbed or
reflected
Object is not seen
at all
The Ray Model of Light
Cardboard
Flat Mirrors
IMAGE:
reproduction of an object
that is produced through
the use of light
REFLECTION:
the bouncing back of
light from a surface
“Mirror, mirror on the wall,
who’s the fairest one of all?”
A PLANE MIRROR
ILLUSTRATES HOW
PREDICTABLE THE
PATH OF LIGHT IS
WHEN IT HITS A
MIRROR.
Plane mirror or flat mirror:
flat, polished surface that reflects an image
INCIDENT RAY
...The original
incoming ray of
light
REFLECTED RAY
...The ray that
bounces off
the mirror
...THE DOTTED
LINE THAT IS
PERPENDICULAR,
OR AT RIGHT
ANGLES, TO THE
REFLECTING
MIRROR
SURFACE
“Normal line” is perpendicular
(90) to the surface
ANGLE OF
INCIDENCE
ANGLE OF
REFLECTION
When light hits an object, it can be…
Transmitted- pass through the
object
Refracted- light bends as it is
absorbed by the object
Reflected- light is scattered away
from the object
p.481 # 3 & 5
Check your answers!
3.
Transparent
Translucent
Opaque
clean glass
frosted glass
textbook
clean air
thin tissue paper
rock
apple juice
sunglasses
5. The normal is a line that is perpendicular to a surface (i.e. 90oC),
touching the surface at the point where a light ray strikes.
The angle of incidence is the angle between the incoming ray and the
normal.
The angle of reflection is the angle between the reflected ray and the
normal.