Curved Mirrors

1
(No Transcript)
2

• There are some mirrors that distort the reflected
  image. Cosmetic mirrors magnify things, and other
  mirrors make things look smaller.

3
Curved Mirrors
4
Curved Mirrors

• A curved mirror is a section of a sphere.
• If the outside surface of the sphere is
  reflecting, the mirror is convex.
• If the inside surface is reflecting, the mirror
  is concave.

5
The characteristics (SALT) of the image formed
can be

• larger, smaller or the same size of the object
• inverted or upright
• in front or behind the mirror
• real or virtual

6
Parts of the concave mirror

• Vertex (V) the centre of the mirror
• Principal Axis (PA) line that goes through V
• Focus (F)where the reflected rays of parallel
  incident rays intersect
• Centre of Curvature (C)the centre of the sphere
  from which the mirror was cut

7
(No Transcript)
8
By drawing ray diagrams, you can find out how the
image would be.

• Draw a ray parallel to the principal axis from
  the top of object to the curved mirror. After
  reflecting off mirror, the ray passes through the
  focal point.

9

• Draw a ray from the top of the object through the
  focal point. The ray will be parallel to the
  optical axis after reflecting.

10

• Draw a ray aimed at the vertex from the top of
  object to the curved mirror. After reflecting off
  mirror, the rays passes at the same angle below
  the principal axis.

11

• Draw a ray aimed at the centre of curvature from
  the top of object to the curved mirror. After
  reflecting off mirror, the ray reflects back on
  itself.

12
Use any two rules to determine the
characteristics of the image.

• Draw the image as a vertical arrow with its tail
  on the principle axis and the head at the point
  where the two reflected rays meet.

13
The characteristics (SALT) of the image formed
are

• smaller
• inverted
• in front of the mirror
• real

14
Useful Websites
http//thinkingoutofthebeaker.ca/DigitalSci/Curved
Mirrors.html
http//www.edumedia-sciences.com/en/a308-concave-m
irror
http//www.shermanlab.com/science/physics/optics/S
phericalMirror.php
15
Practice your ray diagrams on the following. Draw
the image. State the characteristics of each
image.
16
Answers
17
Convex Mirrors
18
Parts of the convex mirror

• Vertex (V) the centre of the mirror
• Principal Axis (PA) line that goes through V
• Focus (F)where the reflected rays of parallel
  incident rays intersect
• Centre of Curvature (C)the centre of the sphere
  from which the mirror was cut

19
By drawing ray diagrams, you can find out how the
image would be.

• Draw ray parallel to principal axis. After
  reflection, this ray travels as if it is coming
  from the focus.

20

• Draw line from top of object to centre, C. After
  reflection, this ray travels back on itself as if
  it is coming from the centre of curvature.

21

• Draw line from top of object to the focus, F.
  After reflection, this ray travels back parallel
  to the principal axis.

22
Use any two rules to determine the
characteristics of the image.

• The virtual image is drawn using a dotted line
  with an arrow.
• Tip Images formed by a convex mirror are always
  smaller, upright, and virtual.

23
Practice

• Practice your ray diagrams on the following. Draw
  the image. State the characteristics of each
  image.