Bai 4 Dinh luat phan xa anh sang

TIẾT 4
ĐỊNH LUẬT PHẢN XẠ ÁNH SÁNG
(THE LAW OF REFLECTION)


BÀI 4. ĐỊNH LUẬT PHẢN XẠ ÁNH SÁNG
( THE LAW OF REFLECTION)
VACABULARY
Reflection :
Image:
Incident ray:
Perpendicularly:
Normal:
Angle:

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BÀI 4. ĐỊNH LUẬT PHẢN XẠ ÁNH SÁNG
( THE LAW OF REFLECTION)
I. PLANE MIRROR
The image of an object observed in mirror is
called the image of an object created by a
plane mirror
C1. Sheet metal smooth and flat, water surface,
glass, ...

II. THE LAW OF REFLECTION
C1. Indicate some objects which
have flat, smooth surfaces and
can be used to see image of our
as a plane mirror


BÀI 4. ĐỊNH LUẬT PHẢN XẠ ÁNH SÁNG
( THE LAW OF REFLECTION)
I. PLANE MIRROR
The image of an object observed in mirror is
called the image of an object created by a
plane mirror

II. THE LAW OF REFLECTION
Phenomenon of light rays coming from the
mirro faces in a definite direction is called
light refrection phenomenon.
1. What plane does the reflected ray lie in?
Conclusion: Reflected ray is in the same
nomal
incident ray and……………..
plane with……………….

C2. Observe and tell what plane
does the reflected ray lie in?


BÀI 4. ĐỊNH LUẬT PHẢN XẠ ÁNH SÁNG

( THE LAW OF REFLECTION)
I. PLANE MIRROR
II. THE LAW OF REFLECTION
1. What plane does the reflected ray lie in?
S

Conclution: Reflected ray is in the same plane with
incident ray and normal.

I

2. How is the direction of a reflected ray
related to the direction of an incident ray?
Angle SIN= i is called angle of incident
Angle NIR= i’ is called angle of reflection
IN lie perpendicularly with the mirror surface
is called normal
Conclusion: An angle of reflection is always
equals
……….angle
of incident

N
R

Angle of
incidence i
600
450
300

Angle of
reflection i’
600
450
300


BÀI 4. ĐỊNH LUẬT PHẢN XẠ ÁNH SÁNG
( THE LAW OF REFLECTION)
I. PLANE MIRROR
II. THE LAW OF REFLECTION
1. What plane does the reflected ray lie in?
Conclusion: Reflected ray is in the same plane with
incident ray and normal.

2. How is the direction of a reflected ray
related to the direction of an incident ray?
Conclusion: An angle of reflection is always equals
angle of incident

3. The law of reflection

Angle of
incidence i
600
450
300

Angle of

reflection i’
600
450
300


BÀI 4. ĐỊNH LUẬT PHẢN XẠ ÁNH SÁNG
( THE LAW OF REFLECTION)
I. PLANE MIRROR
II. THE LAW OF REFLECTION
1. What plane does the reflected ray lie in?
2. How is the direction of a reflected ray
related to the direction of an incident ray?
3. The law of reflection
An angle of reflection is always equals angle of incident
Reflected ray is in the same plane with incident ray
and normal.

4. Ketch a plane mirror and light ray

C3.
S

Incident point

N

I

R

Plane miror


BÀI 4. ĐỊNH LUẬT PHẢN XẠ ÁNH SÁNG
( THE LAW OF REFLECTION)
I. PLANE MIRROR
II. THE LAW OF REFLECTION
1. What plane does the reflected ray lie in?
2. How is the direction of a reflected ray
related to the direction of an incident ray?
3. The law of reflection
An angle of reflection is always equals angle of incident
Reflected ray is in the same plane with incident ray
and normal.

4. Ketch a plane mirror and light ray

III. APPLICATION

S
C4.
I

N

R


BÀI 4. ĐỊNH LUẬT PHẢN XẠ ÁNH SÁNG

( THE LAW OF REFLECTION)
I. PLANE MIRROR
II. THE LAW OF REFLECTION
1. What plane does the reflected ray lie in?
2. How is the direction of a reflected ray
related to the direction of an incident ray?
3. The law of reflection

C4.

III. APPLICATION

I

N
b)

S
R

An angle of reflection is always equals angle of incident
Reflected ray is in the same plane with incident ray
and nomal.

4. Ketch a plane mirror and light ray

S

a)

I

N

R


BÀI 4. ĐỊNH LUẬT PHẢN XẠ ÁNH SÁNG
( THE LAW OF REFLECTION)
Memorize
The law of reflection:
•A reflection ray lies in a plane containing an incident
and a normal of the mirror at an incident point
•The angle of reflection equals the angle of incident