REFLECTION
What is Reflection
�When light bounces off an
opaque surface .
Some terms of reflection
Law of reflection
Normal line, Reflected ray and incident
ray all are in the same plane
Types of Images
�Real Images- mirrors can produce
images that can be projected on a
screen. A real image is ALWAYS
inverted and appears in front of the
mirror.
�Virtual Image- mirrors can also
produce images that cannot be
projected on a screen. A virtual image
is ALWAYS upright and appears behind
the mirror.
Properties of reflection on a plane
mirror
1. Object size = Image Size
2. Object distance from mirror = image
distance from mirror
3. Attitude (orientation) is ALWAYS
upright
4. ALWAYS forms a virtual image
5. Image is reversed - left to right
Types of Mirrors
1. Plane Mirror- a flat mirror that reflects
light rays in the same way that they
approach the mirror.
1. Concave Mirror- a converging mirror
where light rays that strike the mirror
surface are reflected so they
converge or “come together”, at a
point.
3.
Convex Mirrors- a diverging mirror where
light rays that strike the mirror surface
are reflected so that they diverge, or
“go apart” and they never come to a
point.
S.A.L.T
� SALT is used to describe images formed by
mirrors.
1. S- Size: compared to original object is it
same size, smaller or bigger?
2. A- Attitude: which way the image is
oriented compared to the original object
(upright or inverted).
3. L- Location: location of the image (in
front or behind the mirror).
4. T- Type: is the image a real image or
virtual image?
Problem�Example:
�Let’s draw the letter P together in your
copy
P
?
PERISCOPE
A periscope is a useful example of the law of
reflection at work. It’s important that your mirrors
are placed at a 45° angle, because light always
reflects away from a mirror at the same angle that it
hits it. In a periscope, light from an object strikes
the top mirror at 45° and bounces off at the same
angle. This sends light directly down the tube and
onto the lower mirror. This mirror, also at a 45°
angle, reflects light directly to your eye.
Periscopes are used in land and sea
warfare, submarine navigation, and
elsewhere to enable an observer to see his
surroundings while remaining under cover,
behind armour, or submerged.
The End