Pantulan cahaya

1. REFLECTION OF LIGHT
PANTULAN CAHAYA

2. Senarai semak Fizik / Checklist Physics

5. Cermin/Mirror
Sinar tuju
Incidence ray
Sinar pantulan
Reflected ray
AO ialah sinar cahaya yang dituju ke cermin
AO, is the ray of light which strike the mirror
OB ialah sinar cahaya yang dipantul oleh
cermin
OB, is the ray which is bounces back from
the mirror
ON ialah garis yang bersudut tepat dengan
cermin.
ON is a line which is perpendicular to the
surface of a mirror.
Sinar tuju
Incidence ray
A
O
N
B
Sinar pantulan
Reflected ray
Garis normal
Normal line

6. Cermin / Mirror
Garis normal
Normal line
Sinar tuju
Incidence ray
Sinar pantulan
Reflected ray
i r
Sudut antara garis normal dengan
sinar tuju, i
The angle between the normal line
and the incident ray, i
Sudut antara garis normal dengan
sinar pantulan, r
The angle between the normal and the
reflected ray, r
Sudut tuju
Incidence angle
Sudut pantulan
Reflected angle

9. 20⁰ 30⁰ 40⁰ 50⁰ 60⁰

10. Sudut tuju, i = sudut pantulan, r
Incidence angle, i = reflected angel, r
1. Sinar tuju, sinar pantulan dan garis normal
semuanya berada pada satah yang sama.
incidence ray, reflected ray and normal line are
all in the same plane
2. Sudut tuju, i sama dengan sudut pantulan, r.
Incidence angle, i = reflected angle, r

11. Telinga kanan / Right ear

13. • laterally inverted / songsang sisi
• same size / sama saiz
• upright / tegak
• virtual image / imej maya
• Object distance = image
distance
Jarak objek = jarak imej
Huraikan ciri-ciri imej yang dibentukkan oleh cermin satah.
Describe the charac-teristics of the image formed by reflection
of light

14. Real Image is an image
which can be seen or
projected on a screen
Imej NYATA/REAL image
Imej nyata ialah imej yang
boleh dilihat atau
dipancarkan di atas skrin.
screen
object
Real image
/imej nyata Real image
/imej nyata
Real image
/imej nyata

15. Imej MAYA / VIRTUAL image
Virtual Image is an image which cannot be seen on
a screen or cannot be projected on a screen
Imej maya ialah imej yang tidak boleh dilihat atau
dipancarkan di atas skrin
Mirror / cermin
object
Virtual image/ imej maya
Virtual image
imej maya

17. Plane Mirror
Cermin satah
Melukis rajah sinar bagi cermin satah.
Draw ray diagram in a plane mirror
Object
Image
Eyes /mata
u = jarak objek v = jarak imej

18. Plane Mirror
Cermin satah

21. Object
Virtual image / imej maya
Upright / tegak
Same size / sama saiz

23. Senarai semak Fizik / Checklist Physics

24. Pantulan ke atas cermin melengkung
Reflection on a Curved Mirror
1. Terdapat dua jenis cermin:
There are two type of curved mirrors:
(a) Concave mirror, which curves
_______
(b) Convex mirror which curves
___________
Ke dalam / Inwards
Keluar / outwards

26. Cermin cekung – imej tegak & besar
Concave Mirror – image upright and big

27. Cermin Cekung
Concave Mirror
Imej songsang & kecil
Image inverted and small

28. Cermin Cembung: Imej sentiasa kecil dan tegak
Convex mirror:Image always small and upright.

29. Cermin Cembung: cermin sisi kereta
Convex mirror: side mirror of car

31. Cermin Satah
Plane Mirror
Sinar cahaya dipantulkan melalui lintasan yang sama
The parallel rays is reflected back to the same path.

32. Cermin cekung: menumpu
Concave mirror: converge
Cermin cembung: mencapah
Convex mirror: diverge

33. Paksi utama
Principle axis
P = kutub cermin
Pole of the mirror
P
F
F = Titik Fokus
Focal point
Cermin Cekung
Concave Mirror
Sinar selari dipantulkan dan menumpu pada TITIK FOKUS
The parallel rays is reflected and CONVERGE at a FOCAL POINT

34. Principle axis
P = Pole of
the mirror
P
F
F = Focal point
The parallel rays is
reflected and DIVERGE as
it comes from a FOCAL
POINT behind the mirror
Convex Mirror
Sinar selari dipantulkan
dan dicapahkan seolah-
olah ia datang dari titik
fokus di belakang cermin

35. Sinar selari dipantulkan pada lintasan yang sama.
The parallel rays is reflected back to the same path.
Sinar selari ditumpukan di TITIK FOKUS selepas dipantulkan
The parallel rays is CONVERGE at a FOCAL POINT after reflection
Sinar selari dipantulkan dan mencapah seolah2 dari TITIK
FOKUS di belakang cermin
The parallel rays is reflected and DIVERGE as it comes from
a FOCAL POINT behind the mirror

37. Kaca sfera berlubang/ Hollow glass sphere
Cermin Cekung
Concave mirror
Cermin Cembung
Convex mirror

38. Paksi Utama
Principal axis
Garisan yang melalui pusat kelengkungan, C
dan kutub cermin, P
The line which passes through the centre of
curvature, C and the pole of a mirror, P
C
C
F
F
Istilah berkaitan cermin melengkung
The terms regarding the curve mirror

39. Pusat
kelengkungan
Centre of
curvature, C
Pusat cermin cekung / cembung
Center of the concave / convex mirror
C
C
F
F
Istilah berkaitan cermin melengkung
The terms regarding the curve mirror

40. Kutub cermin
Pole of mirror,
P
Titik tengah bagi cermin melengkung
Middle point on the curved mirror.
C
C
F
F

41. Titik fokkus
Focal point,F
Titik di mana semua sinar selari ditumpukan
selepas dipantulkan
A point through which all rays traveling parallel
converge after reflection.
C
C
F
F

42. Panjang focus
Focal length, f
Jarak antara titik focus, F dan kutub
cermin, P
The distance between the focal point, f
and the pole of the mirror, P.
C
C
F
F
f
f

43. Jarak objek, u
Object distance, u
Jarak antara objek
dengan kutub cermin, ,P
Distance of object from
the pole of the mirror, P
Jarak imej, v
Image distance, v
Jarak antara imej dengan
kutub cermin, P
Distance of image from
the pole of the mirror, P

44. Draw ray diagrams to show
the positioning and
characteristics of the image formed by
a
convex mirror
concave mirror

45. Senarai semak Fizik / Checklist Physics

47. Peraturan melukis rajah sinar bagi cermin cekung
Construction Rules for drawing ray diagram for concave mirror
Sinar selari dengan
paksi utama
dipantulkan ke titik F.
A ray parallel to the
principal axis is
reflected through F.
Sinar melalui titik F
dipantulkan selari
dengan paksi utama.
A ray passing through F
is reflected parallel to
the principal axis
Sinar melalui titik C
dipantulkan semula
ikut lintasan sama.
A ray passing through C
is reflected back along
the same path.

48. Sinar selari dengan
paksi utama
dipantulkan ke
titik F.
A ray parallel to
the principal axis is
reflected through
F.

49. Sinar melalui titik F
dipantulkan selari
dengan paksi
utama.
A ray passing
through F is
reflected parallel
to the principal
axis

50. Sinar melalui titik
C dipantulkan
semula ikut
lintasan sama.
A ray passing
through C is
reflected back
along the same
path.

52. Peraturan Melukis Rajah Sinar bagi Cermin Cembung.
Construction Rules for drawing ray diagram for convex mirror
Sinar selari dengan paksi
utama dipantulkan seolah2
ia datang dari titik F.
A ray parallel to the principal
axis is reflected as if it comes
from F.
Sinar dipancarkan ke titik F
dipantulkan selari dengan
paksi utama
A ray directed towards F is
reflected parallel to the
principal axis.
Sinar dipancarkan melalui
titik C dipantulkan
sepanjang lintasan yang
sama.
A ray is directed towards C is
reflected back along the
same path.

53. Menentukan kedudukan dan ciri-ciri
imej dengan rajah sinar bagi cermin
cekung.
1- Sinar selari dipantulkan ke F / A ray parallel is reflected through F.
2- Sinar melalui F dipantulkan selari. / A ray passing through F is reflected parallel.
3- sinar melalui C dipantulkan ikut lintasan yang sama. / A ray passing through C
reflected along the same path.
C F
Object
4- Pertemuan garis-garis ini ialah kedudukan imej / The intersection of the lines is the
position of an image
Image
Determining the position and
characteristics of an image with a Ray
Diagram for CONCAVE MIRROR

54. Convex Mirror
1- A ray parallel to the principal axis is reflected as if it came from
F.
2- A ray which appears to came from F is reflected parallel to
principal axis.
3- A ray which appears to come from C strikes the mirror at right
angles and returns along the same path away from C.
F C

55. Cermin Cekung
Concave Mirror
Skrin / Screen
Objek / Object

60. Cermin Cekung / Concave mirror Cermin cembung
convex mirror

61. Rajah sinar bagi cermin cekung
Ray Diagram for concave mirror (u>2f or u > C)
Image characteristics:
1- Real / Nyata
2- Inverted / Songsang
3- Diminished / Kecil
4- f < v < 2f

62. Cermin Cekung / Concave mirror (u = 2f or u = C)
Image characteristics:
1- Real / Nyata
2- Inverted / Songsang
3- Same size / Sama saiz
4- v = 2f = C

63. Rajah sinar bagi cermin cekung
Ray Diagram for concave mirror (f < u < 2f)
Image characteristics:
1- Real / Nyata
2- Inverted / Songsang
3- Magnified / Besar
4- v > 2f

64. Rajah sinar bagi cermin cekung
Ray Diagram for concave mirror (u = f)
Image characteristics:
1- Virtual / maya
2- upright / tegak
3- Magnified / besar
4- Image at infinity /
imej di infiniti

65. Rajah Sinar bagi cermin Cekung
Ray Diagram for Concave mirror (u < f)
Image

66. Ciri imej / Characteristics of image (u < f)
3- Magnified / besar
1- virtual / maya
2- upright / tegak

67. Real, Inverted, Diminished
RID
Real, Inverted, Same size
RIS
Real, Inverted, Magnified
RIM
Virtual, Upright, Magnified
VUM
Virtual, Upright, Magnified
VUM

68. Imej nyata : u > 2f , f < u < 2f, u = 2f
Real image
Semakin berkurang jarak objek, u,
semakin bertambah jarak imej, v
u berkadar songsang dengan v
The less the object distance, u, the
further the image distance, v
u inversely proportional to v
Semakin berkurang jarak objek, u,
semakin besar saiz imej
u berkadar songsang dengan saiz imej
u inversely proportional to size of image

69. Senarai semak Fizik / Checklist Physics

70. F F 2F
C
Object Image
Rajah sinar bagi cermin cembung
Ray diagram for convex mirror
Ciri-ciri imej / Characteristics of image:
Maya, tegak, kecil
Upright, virtual and smaller

71. Senarai semak Fizik / Checklist Physics

73. Menggunakan cermin anti paralaks pada ammeter. Penunjuk
ammeter selari dengan imej penunjuk dalam cermin.
Use anti parallax error mirror of an ammeter. The pointer of
ammeter overlaps the image of the pointer in the mirror
imej
Imej dan penunjuk tidak selari
– ralat paralaks
Imej and pointer are not in line
– parallax error.

74. Imej dan penunjuk tidak selari
– ralat paralaks
Imej and pointer are not in line
– parallax error.
Tiada ralat paralaks
No parallax error.

75. Cahaya dari objek dipantulkan oleh
cermin pertama ke cermin kedua dan
dipantulkan ke dalam mata
Light from the object is reflected by the
first mirror to the second mirror. It is
reflected to the eyes.
Imej maya, tegak, sama saiz.
Image is virtual, upright, same size.

76. Periskop dalam
kereta untuk melihat
trafik di hadapan.
Periscope in the car to
see ahead in traffic

77. Supaya imej yang dilihat dalam
cermin kereta di hadapan kelihatan
tegak .
The image seen in the mirror of the
car in front is upright.

78. Cermin cekung / Concave mirror
u < f
Maya, tegak, besar
Virtual, upright dan magnified.
Cermin cekung digunakan untuk
mendapatkan imej muka yang besar dan
tegak.
Concave mirror is used to create a
magnified and upright image of the face.

79. Imej Maya, tegak, sama saiz
Image Virtual, upright, same size.
Imej Maya, tegak, besar
Image Virtual, upright, magnified.
Untuk make-up muka gadis mesti dekat dengan cermin cekkung. Jarak
objek mesti kurang dari panjang fokus, f ( u < f)
For make-up the lady’s face must be close to the concave mirror. The
object distance has to be less than the focal length, f.

80. Cermin cekung / Concave mirror
Pada titik fokus / At focal point / u = f
Semua gelombang tuju dari
satelit (jauh) datang secara
selari dan akan ditumpukan
selepas dipantulkan.
The incidence waves from the
satellite (distant object) are
parallel and will focus at focal
point after reflection.

82. Cermin cekung / Concave mirror
Pada titik fokus pemantul
At the focal point of the reflector.
Cahaya daripada bulb lampu akan
menuju ke pemantul dan
dipantulkan selari. Dapat melihat
objek yang berada jauh di depan.
Light from the bulb at f, hit the
reflector and will reflect parallel.
Can see distant object ahead.

83. High beam: Mentol di F,
cahaya dipantulkan selari
untuk lihat objek jauh di
depan.
bulb at F, light reflected
parallel to see distant object
in front
Low beam High beam

84. Cermin cekung / Concave mirror
u < f
Maya, tegak, besar / virtual, upright, magnified

85. Cermin cembung / Convex mirror
Medan penglihatan besar. Pemandu boleh lihat
objek di belakang dan di sisi kereta /
wider view of vision. Driver can see object at
the back and at the side of the car / blind spot

86. Cermin cembung / Convex mirror
Cahaya dari kereta di depan
dipantulkan oleh cermin ke pemandu.
Pemandu lihat imej tegak dan kecil,
luas medan penglihatan./ light from the
car ahead is reflected by the mirror to
the driver. He can see an upright and
small image, wider view of vision.

87. In supermarket for safety purposes.
Imej yang dihasilkan oleh cermin cembung sentiasa
maya, kecil dan tegak. Dapat melihat keadaan
kedai.
The image produced by convex mirror is always
virtual, smaller and upright. Can see the whole
shop.

88. Convex and Concave Mirrors
Images in convex mirrors Images in concave mirrors
are always smaller. are always bigger