Chapter 5
The Law of reflection allows mirrors to form images
Section 5. 1 – The Ray Model of Light
The ray model of light can be
used to understand how light
moves in straight lines, reflects
off mirrors and refracts through
lenses.
In order for you to see an object,
it must reflect some light back to
your eyes.
Sir Isaac Newton believed that
light is a stream of fast-moving,
unimaginably tiny particles.
A ray is an imaginary line
showing the direction in
which light is traveling
Transparent Materials – allows light to pass freely through it.
Only a small amount of light is absorbed and reflected.
Translucent Materials – most light rays get through, but are
scattered in all directions. They do not allow objects to be
seen distinctly.
Opaque Materials – prevents any light from passing through
it. It only absorbs and reflects light.
Rectilinear Propagation –
light travels in a straight line.
The distance from a light
source affects the size of the
shadow that an object
makes.
The closer an object is to a
light source, the smaller the
shadow.
Page 175, Questions 1 -4
Reflection – 2 different types
1. Specular Reflection – reflection from a mirror-like
surface, which produces an image of the
surroundings.
Specular Reflection
2. Diffuce Reflection – reflection from a rough
surface, which does not produce a clear image but
instead allows you to see what is on the surface.
An example of Diffuce Reflection
Diffuse reflection allows you to
read print on a page. The black
ink, on a white page, will absorb
most of the light. The white page
will reflect rays which go out in all
directions.
Page 177, Questions 1 - 3
Law of Reflection
The angle of reflection of a light ray is equal to the
angle of incidence, or the angle at which the ray
strikes the reflecting surface.
Refraction
The bending of light, when it travels from one
medium to another.
Light being refracted through a prism
Angle of incidence (i)
Angle of Reflection ( r )
Angle of Refraction (R)
Page 181, Questions 1 – 3
Read Pages 181 – 182
Page 182, Questions 1 - 2
Core Lab – Follow that Refracted Ray
Lab write up – page 184 & 185
Questions 3 – 8 page 185
Page 187, Questions 1 – 11
Page 171, Foldable - 1st 2 sections
Section 5.2 Images in Plane Mirrors
Using Mirrors to Form Images
All mirrors reflect light
according to the law of
reflection.
A flat smooth mirror is
called a plane mirror.
The mirror on the wall, in
your bathroom, is
probably a plane mirror.
Plane Mirrors
Plane mirrors form an image that is upright and
appears to be as far behind the mirror as the
object is in front of it.
Left and right appear to be reversed in a plane
mirror.
Page 191,
Questions 1 - 3
Core Lab – Demonstrating the Law of Reflection
Lab Write Up – Page 192 & 193
Analyze Questions: 1 – 3
Conclude and Apply Questions: 1 -3
Lab Write Up – Page 194
Analyze Questions: 1 – 2
Conclude and Apply Questions: 3 – 4
Page 195, Questions: 1 – 6
Foldable – Section 3
Section 5. 3 – Images in Curved Mirrors
Concave Mirrors
A concave mirror is a mirror that curves inward.
Light reflecting off a concave mirror meet at a single
point called the focal point.
Light rays that come together are called converging rays.
Flashlights, car headlights, and telescopes, are a few
applications of concave mirrors.
The image formed by a concave mirror
depends on the location of the object.
A ~ object outside 2 focal
point lengths; image is
smaller and inverted and
real
B ~ object is between F
and 2F; image is larger
and inverted and real
C ~ object is between F
and mirror; image is
larger and upright and
virtual
Page 202, Questions: 1 - 4
Convex Mirrors
A convex mirror
is a mirror that
curves outwards.
Reflected rays
from a convex
mirror diverge
and do not meet.
The image formed by a convex mirror have
these characteristics:
Image is smaller than the object.
The image distance is smaller than
the object distance.
The image is upright.
The image is virtual.
More objects can be seen in a
convex mirror than in a plane
mirror.
Using Lenses to Form Images
A lens is a piece of
transparent material that can
bend, or refract, light rays in
useful ways to help form a
well-focused image.
A lens can be concave or
convex.
Concave Lenses
Concave lenses are thinner in the middle than at the edge.
Concave lenses cause light rays to diverge.
Concave lenses produce images that are upright and
smaller than the object.
Concave lenses are sometimes used in eyeglasses and
telescopes.
Convex Lenses
Convex lenses are thicker in the middle
than at the edge.
Convex lenses cause light rays to
converge.
When parallel rays strike a convex lens
they come together at the focal point.
A magnifying glass is a good example
of a convex lens.
Focal length in Convex Lenses
The distance from the centre of the lens to the focal
point is called the focal length.
The type of image a convex lens forms depends
on where the object is relative to the focal
point.
Page 206, Questions: 1 – 3
Page 209, Questions: 1 – 12
Foldable – Remaining Sections
Chapter Review Questions, Page 210