2. GOOD
MORNING!

3. 1. Have you seen a mirror?
2. Do you have a mirror at home?
3. What is the purpose of using a
mirror?
3
QUESTIONS:

4. 1. What did you see on the mirror?
2. Have you ever wondered how mirrors
form images?
3. What do you think will be the content of
our discussion for today?
4. What do you know about reflection?
4
QUESTIONS:

5. REFLECTION

6. OBJECTIVES:
✘ Define the terms reflection, angle of
incidence, angle of reflection, incident ray,
and reflected ray.
✘ Compare the angle of incidence and angle
of reflection, and state the law of
reflection.
✘ State the importance of reflection in daily
life.
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7. Video Presentation
Let’s watch this!
7

8. Let’s have an activity!
ACTIVITY 1
Angle of Incidence vs. Angle of Reflection

10. RUBRICS

11. ACTIVITY OBJECTIVES:
✘ Compare the Angle of Incidence
and Angle of Reflection
✘ State one of the Laws of
Reflection.
11

12. MATERIALS
•1 plane mirror
•1 low frequency laser / laser pen
•1 paper protractor
•clay for support
12

13. PROCEDURE:
1. Let the mirror stand vertically
along the edge of the paper
protractor as shown in figure 1.
Use the clay to support the
plane mirror.
13

14. PROCEDURE:
14
Figure 1. A plane mirror on a plane protractor

15. PROCEDURE:
2. Position the laser beam such
that it hits the mirror at an angle
of 10⁰ with the normal line.
Record your measurement in a
table similar to table 1.
15

16. PROCEDURE:
16
Table 1. Angles of Incidence and Reflection

17. PROCEDURE:
3. Make three trials and get the
average.
17

18. PROCEDURE:
4. Repeat steps 2 to 4 for angles
20⁰, 30⁰, 40⁰, and 50⁰. Enter all
your measurements in Table 1.
18

19. PROCEDURE:
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Table 1. Angles of Incidence and Reflection

20. GOODLUCK!
20

21. PRESENTATION OF OUTPUT
21

22. LET’S CHECK!
22

23. ANALYSIS OF THE ACTIVITY:
1. Have you arrived with the
same results considering the
three trials of five different
angle of incidence?
23

24. ANALYSIS OF THE ACTIVITY:
24

25. ANALYSIS OF THE ACTIVITY:
2. How does the angle of
incidence compare with the
angle of reflection?
25

26. ANALYSIS OF THE ACTIVITY:
THE ANGLE OF INCIDENCE IS
EQUAL TO THE ANGLE OF
REFLECTION
26

27. ANALYSIS OF THE ACTIVITY:
3. A periscope is an instrument
for observation over, around or
through an obstacle.
27

28. ANALYSIS OF THE ACTIVITY:
a. Explain how light travels in a
periscope.
b. Diagram the light rays as it
pass through the periscope.
28

29. ANALYSIS OF THE ACTIVITY:
29

30. ANALYSIS OF THE ACTIVITY:
Light enters the periscope
and reflected at an equal
angle and again reflected by
another mirror.
30

31. LET’S ELABORATE!
1. What do you mean by
reflection?
31

32. LET’S ELABORATE!
REFLECTION is the bouncing
off of light rays when it hits a
surface like a plane mirror.
32

33. LET’S ELABORATE!
2. What is an incident ray? A
reflected ray? A normal
line?
33

34. LET’S ELABORATE!
34

35. LET’S ELABORATE!
✘ Incident Ray – is the ray of
light approaching the mirror
represented by an arrow
approaching the mirror.
35

36. LET’S ELABORATE!
✘ Reflected Ray – is the ray of
light which leaves the
mirror and is represented
by an arrow pointing away
from the mirror.
36

37. LET’S ELABORATE!
✘ Normal Line – is an
imaginary line that can be
drawn perpendicular to the
surface of the mirror at the
point of incidence where the
ray strikes the mirror.
37

38. LET’S ELABORATE!
3. What do you mean by the
Angle of Incidence? Angle
of Reflection?
38

39. LET’S ELABORATE!
✘ Angle of Incidence– is the
angle between the incident
ray and the normal line.
39

40. LET’S ELABORATE!
✘ Angle of Reflection– is the
angle between the reflected
ray and the normal line.
40

41. LET’S ELABORATE!
41

42. LET’S ELABORATE!
4. What does the law of
reflection states?
42

43. LET’S ELABORATE!
The
Angle of Incidence
is equal to the
Angle of Reflection.
43

44. Application and Valuing
Can you give examples
where the importance of
reflection is applied in daily
life?
44

45. Assess your Learning!
45

46. Identification
___________1. is the bouncing off
of light rays when it hits a
surface like a plane mirror.
46

47. Identification
___________2. is the ray of light
which leaves the mirror and is
represented by an arrow
pointing away from the mirror.
47

48. Identification
___________3. is an imaginary line
that can be drawn
perpendicular to the surface of
the mirror.
48

49. Identification
___________4. is the angle between
the reflected ray and the
normal line.
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50. Identification
5-7. State the Law of Reflection
8-10. Give atleast one
importance of reflection
in daily life
50

51. Identification
11-15. Light is incident on a flat
surface (a plane mirror),
making an angle of 25⁰ with that
of the surface.
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52. Problem Solving
a. Find the angle of incidence.
b. Find the angle of reflection.
c. Find the angle made by the reflected
ray and the surface.
d. Find the angle made by the incident
and reflected ray.
52

53. Assignment:
1. Study and read about
images formed by curved
mirrors.
53

54. THANK YOU!
Good Job!
54