Topic Slides Minutes1 Displacement 9 27

2 Vectors 13 39

3 Kinematics 13 39

4 Graphs 10 30

5 Energy 10 30

6 Power 5 15

7 Springs 4 12

8 Shadows 3 9

9 Field of Vision 7 21

10 Colors 3 9

11 7 2112 Convex mirrors 4 12

13 Refraction 5 15

14 Lenses 10 30

15 Optical Power 6 18

Concave Mirrors

The law of reflection, therefore, simply states that when a ray oflight is reflected from a surface, it is reflected in such a directionthat the incident angle equals the reflected angle.

Using the law of reflection, we can determine the location of images formed by plane mirrors.

xx

o

o

Converges light Diverges lightBrings it together Spreads it out

Converging mirror Diverging mirror

F

Concave mirrors

C

Backofmirror

Principal axis

Radius of curvature

fFocal length

V(vertex)

Center of curvature

Focal point

NOTEThe focal length (f) is half the radius of curvature.

Click

A ray parallel to the principal axis is reflected through the

focal point (F).

In order to draw images formed by curved mirrors, remember that :

FCPrincipal axis

Back of mirror

V

Click

A ray that goes through the focal point (F) is reflected parallel to

the principal axis.

In order to draw images formed by curved mirrors, remember that :

FCPrincipal axis

Back of mirror

V

Click

A ray that strikes the vertex (V) is reflected like a plane mirror. (Angle of

incidence = Angle of reflection)

In order to draw images formed by curved mirrors, remember that :

FCPrincipal axis

Back of mirror

V

Incident ray

Reflected ray

Incident ray

Reflected ray

Click

A ray that goes through C(the center of curvature) is reflected back

along its own path.

In order to draw images formed by curved mirrors, remember that :

FCPrincipal axis

Back of mirror

V

F

Concave mirrors

C

Backofmirror

Principal axis

Object at infinity (very far away)

All rays arrive parallel to the principal axis

All rays reflectthrough F

No Image formed

F

Concave mirrors

C

Backofmirror

Principal axis

Object

Image

do is positiveObject beyond C

d i is positive

h i is negative

M is negative and 1

do is positive

ho is positive

d i

do

Real

F

Concave mirrors

C

Backofmirror

Principal axis

Object

Image

d i is positive

h i is negative

M is negative and 1

do is positive

ho is positive

Object beyond C

do is positive

ho is positive

Real

F

Concave mirrors

C

Backofmirror

Principal axis

Object

Image

do is positive

ho is positive

d i is positive

h i is negative

M is negative and 1

Object beyond C

Real

F

Concave mirrors

C

Backofmirror

Principal axis

Object

Image

do is positive

ho is positive

d i is positive

h i is negative

M is negative and 1

Object beyond C

Real

F

Concave mirrors

C

Backofmirror

Principal axis

Object

Image

d i is positive

h i is negative

M is negative and = 1

do is positive

ho is positive

Object at center of curvature

Real

F

Concave mirrors

C

Backofmirror

Principal axis

Object

Image

d i is positive

h i is negative

M is negative and 1

do is positive

ho is positive

Object between C and F

Real

F

Concave mirrors

C

Backofmirror

Principal axis

Para

llel

do is positive

ho is positive

Object at focal point

No Image formed

Concave mirrors

FC

Backof mirror

Principal axis

Div

ergi

ng

do is positive

ho is positive

Object within focal length

Concave mirrors

FC

Backof mirror

Principal axis

Div

ergi

ngd i

d i is negative

h i is positive

M is positive and 1

Image

do is positive

ho is positive

h i

Object within focal length

Virtual

Click

The diagram below represents an object placed in front of aconcave mirror whose centre of curvature is at point C.

Which of the following best represents the image formed bythe mirror?

A) B)

C) D)

F

Concave Mirrors Slide:

A) Real and upright

B) Real and inverted

C) Virtual and upright

D) Virtual and inverted

E) No image is formedClick

An object is placed at point P in front of a concave mirror.

Which of the following are the characteristics of the image.

F

Image

Draw F which is midwaybetween C and mirror.

Concave Mirrors Slide:

Image

Click

Concave Mirrors Slide:

Click

Concave Mirrors Slide:

Normal

Click

Conca

ve M

irro

rs

Slide:

A real image formed in front of a curved mirror is always:

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A) Smaller than the object

B) Larger than the object

C) Upright

D) Inverted

Image

Not always!

Concave Mirrors Slide:

Look!

Image

Click

Concave Mirrors Slide:

… and good luck!