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Pengemudi memanfaatkan pemantulan cahaya pada cermin 
A. Cahaya 
B. Pemantulan 
Cahaya 
C. Pembiasan 
Cahaya 
D. Alat-Alat Optik 
Cahaya dan Optika 
Hasil yang harus Anda capai: 
menerapkan prinsip kerja alat-alat optik. 
Setelah mempelajari bab ini, Anda harus mampu: 
,5C91@81A9=1DB91C941;1;1@5A18C5A5@1B41A93181H1	541 
2541 49 B5;5997 41 41@1C C5A981C ;1A51 141H1 3181H1	 181H1 
:D71 H17 =5=2D1C 41 41@1C =5981C 21H171 41 49 35A=9	 
D7;9 41 @5A18 =5=5A81C9;1 ;131 B@9? @141 =?29 1C1D 
B5@541=?C?A	$131B@9?@141=?2941B5@541=?C?A=5AD@1;1B52D18 
35A=9 35=2D7 H17 497D1;1 @575=D49 DCD; =5981C 1D9C1B 
49 251;17 =?29 1C1D B5@541 =?C?A	 571 =5981C ;131 B@9? 
@575=D49 41@1C 25A25?; 25A85C9 1C1D =5418DD9 ;541A11 19 
4571 1=1	 
)141 ;131 B@9? C5A:149 @5=1CD1 3181H1 B589771 41 41@1C 
=5981C21H17125412541H1725A1414945@1H1	1@1C;1841 
=57945C969;1B9 B961CB961C 21H171 @141 35A=9 ;131 B@9? 
,51935A=935=2D725A41B1A;125CD;H11414D1:59B35A=9 
19H1 H19CD 35A=9 41C1A 41 35A=9 35;D7	 1@1C;18 ;54D1 35A=9 
99 =55ADB;1 3181H1 1719=11 B961CB961C 21H171H1 
41 41@1C =55CD;1 :1F121 @5AC1H11@5AC1H11 C5AB52DC 
411= 212 99	 (58 ;1A51 9CD @51:1A918 212 99 4571 219;	 
107 
• menganalisis alat-alat optik secara kualitatif dan kuantitatif; 
• menerapkan alat-alat optik dalam kehidupan sehari-hari. 
cembung kaca spion. 
Bab 
6 
Sumber: Dokumentasi Penerbit
Tes Kompetensi Awal 
!(%(/700(03(/$-$4,.215(3$+$:$'$136,.$.(4-$.$1/$+52$/52$/%(4,.76'$/$0%7.7/$6,+$1
@1@5A254111C1A121H171=1H14121H171 

	 1719=11B961C21H171@14135A=9 
	 @1H1749=1;BD44571@5=291B1945;B291B 
A. Cahaya 
,19B41C5;??79B51D=5=21F141DCD;=1=@D=5=181=9 
11=	 !1 99 49B5212;1 B19B 41 C5;??79 B51D =5=25A9 @575C18D 
1 21AD B5AC1 9BCAD=5 21AD H17 =1=@D =57D7;1@ A181B91A181B91 
11= B5;19@D 75:11 11= H17 B5=D1 491771@ C941; =D7;9 
C5AD7;1@	 5?=51 1BCA??=9 41@1C 5298 21H1; C5AD7;1@ ;1A51 
C5AB5491H1 C55B;?@ 1C1D C5A?@?7 H17 5298 219; 41A9@141 B525D=H1	 
$5=1:D1 41 @55=D1 411= 29??79 =?45A C941; 41@1C C5A:149 :9;1 
C941; 141 =9;A?B;?@	 1719=11 11C11C ?@C9; C5AB52DC 25;5A:1 41 
=1=@D=57D7;1@A181B9111=11=212991;1492181BB5:D=18 
8D;D= B5AC1 @A9B9@ ?@C9;1 75?=5CA9 @5=1CD1 41 @5=291B1 H17 
49C5A1@;1 411= 2525A1@1 11C ?@C9;	 
1. Teori-Teori tentang Cahaya 
5A9;DC 1;1 49:51B;1 2525A1@1 C5?A9 C5C17 3181H1	 
a. Teori Partikel 
)141)5AC571811214;5
89771@5AC571811214;5L
B5:1A18 9B9;1 B171C 49@571AD89 ?58 @5=9;9A1 41 ;1AH1 5$$ '(9621 
=5B;9@DC5A41@1CB5:D=18C?;?825B1A19H17894D@B5I1=14571 
'5FC?H17=5=25A9;1;?CA92DB925B1AC5A8141@9B9;1	;1C5C1@9 
49 1C1A1 =5A5;1 141 B521791 H17 C941; B5@541@1C 4571 (9621 
49 1C1A1H1  2%(46 22.(  2%(46 2:/( +4,56,$1 7:*(15 /( 
 2(0(4 $0(5 4$'/(: 41 '021'$//(:	 
)141
(9621=55A29C;1;1AH19=918@5AC1=1C5C173181H1 
41 F1A1 411= %),/,-% ) .+/ 0,+/	 $5A:1 9=918 99 49C5A9=1 
4571 219; ?58 B5=D1 @981; ;53D19 22.( 41 7:*(15	 5A5;1 
;525A1C14571(962125A;19C14571@5A3?211H17=5=2D;C9 
;1 218F1 3181H1 C5A49A9 1C1B @1AC9;5 ;539 H17 25A75A1;	 5A5;1 
=571771@ 218F1 3181H1 =5AD@1;1 75?=217	 
-5?A9 @1AC9;5 41@1C =5:51B;1 218F1 @5A1=21C1 3181H1 25AD@1 
71A9B DADB H17 C941; 41@1C 49981C 41A9 251;17 B52D18 @578117	 
41@D75?=217B5@5AC975?=2172DH9=1B9841@1C494571AF11D@D 
49 251;17 C5A41@1C @578117	 )141 1214
(9621 =55=D;1 
;?=@?B9B93181H1@DC98H17499C57A1B9;1457165?=51F1A1	.@1H1 
99=5AD@1;1C9C9;1F1;1:91;8DBDBC5C173181H1H17=5:14941B1A 
2179 9B9;1 =?45A	 (9621 C5AC1A9; =51;D;1 @57D:91 =577D1;1 
@A9B=141;131	$5C9;13181H1491A18;1@141@A9B=13181H1@DC9841@1C 
=5=D3D;1 21H1; F1A1 B5@5AC9 E9?5C 9497? 29AD 89:1D ;D97 
?A1H5 41 =5A18	 (9621 :D71 21H1; =51;D;1 5;B@5A9=5 49 11= 
4571 =5491 B5@5AC9 =9H1; 19A 41 755=2D7 B12D	 5A41B1A;1 
H1C1 
A51C9641945;B291B=DC1; 
Christian Huygens 
(1580 – 1626) 
Sumber: Jendela Iptek, 1997 
108 Mudah dan Aktif Belajar Fisika untuk Kelas X 
	 1719=11 B961C 5B1 35=2D7 41 5B1 35;D7 
C5A8141@25A;1B3181H1H17=55F1C9H1 
	 ,52DC;12525A1@1=1611C5B1H1741;5C18D9	 
Tokoh 
Seorang fisikawan Belanda, 
Christian Huygens dilahirkan di 
Den Haag, pada 14 April 1626. 
Ayahnya seorang diplomat dan 
sastrawan. Pada 1666, ia 
memberikan sumbangan penting 
tentang ilmu Matematika, 
Astronomi, Optik, dan Mekanika, 
yang membuat namanya terkenal 
sebagai ilmuwan penting di Eropa. 
Pada 1655, Huygens menyempurna-kan 
teleskopnya yang cukup kuat 
untuk menemukan sebuah satelit 
Planet Saturnus, kemudian diberi 
nama Titan. Pada awal 1660-an ia 
menemukan lensa pelihat (okuler) 
yang terdiri atas gabungan lensa, 
guna mengurangi gangguan warna 
yang timbul akibat penggunaan 
lensa-lensa non-akromatik, lensa ini 
masih dipakai sampai sekarang.
1719=11 89@?C5B9B 7:*(15 B589771 491 25A 
@541@1C218F13181H1=5AD@1;175?=217 
	 @1 ;55=181 C5?A9 75?=217 H17 =5=2D1C 
(9621=1B98C941;B5CD:D4571C5?A99CD 
	 5DADC 41 49 1C1A1 C5?A9 @1AC9;5 41 C5?A9 
75?=217=11;18H17@197251A 
Gambar 6.1 
Pemantulan baur 
Cahaya dan Optika 109 
@559C91H1 (9621 =5H9=@D;1 218F1 @141 D=D=H1 3181H1 
C5A49A9 1C1B B5;D=@D1 @1AC9;5 H17 49B52DC ,.-1/ )/	 
b. Teori Gelombang 
)141
7:*(1525ADB181=51F1-5?A9)1AC9;54571=5H1C1 
;1218F13181H1=5AD@1;175?=217H1725A75A1;4571;535@1C1 
C5AC5CD 411= =549D= 5C5A	 
5DADC 7:*(15 C9C9;C9C9; @141 =D;1 75?=217 H17 =5A1=21C 
41@1C 491771@ B521719 75?=217 21AD	 )141 75?=217 97;1A1 =D;1 
75?=217H1 25AD@1 97;1A1 B5417;1 @141 75?=217 41C1A =D;1 
75?=217H125AD@171A9BDADB	-5?A975?=21741@1C=5H1;9;1218F1 
1:D 3181H1 411= 19A 5298 1=21C 41A9@141 49 D41A1	 571 45=9;91 
=5DADC7:*(15-5?A9)1AC9;5(96217D7DA	011D@D 45=9;91C5?A9 
75?=217  C941; =1=@D =5:51B;1 C5C17 @5A1=21C1 3181H1 25AD@1 
71A9B DADB	 $55=181 99 H17 =5H5212;1 (9621 C941; B5CD:D 4571 
C5?A9 75?=217	 -5?A9 7:*(15 =1=@D =55=D;1 AD=DBAD=DB @5= 
291B1 41 @5=1CD1 3181H1 4571 B171C =5=D1B;1	 
Tes Kompetensi Subbab A 
(4-$.$1/$+'$/$0%7.7/$6,+$1
5DADCC5?A9@1AC9;541C5?A975?=2171@1;18 
3181H19CD 

	 (962125A@541@1C218F13181H1=5AD@1;1@1A 
C9;5	 5A9;1 @5:51B1 =57519 C5?A9 99 4571 
;19=1C41B549A9	 
B. Pemantulan Cahaya 
1217 9=D @575C18D1 C5C17 3181H1 H17 =5=@51:1A9 B961C 
B961C@5A1=21C13181H1B5@5AC9@5=1CD1@5=291B1B5AC1@A9B9@:11 
H1 B91AB91A 49B52DC ,-0( $,*0. 11= ?@C9;1 75?=5CA9 3181H1 
41@1C 4971=21A;1 4571 B91A 25AD@1 71A9B H17 C571; DADB 4571 
=D;175?=21741C941;B5@5D8H1=5=@5A89CD7;1B961C75?=217 
41A9 3181H1 C5AB52DC	 )5771=21A1 3181H1 B521719 B91A 25AD@1 71A9B 
DADB C941; 41@1C 49C5A1@;1 411= ,-0( #// )141 ?@C9;1 69B9B 3181H1 
81ADB B5@5D8H1 49@1417 B521719 75?=217 ;1A51 565; 565; 
9C5A65A5B9 41 496A1;B9H1 B171C 4?=91	 
1. Pemantulan Baur dan Pemantulan Teratur 
)141 D=D=H1 B5C91@ @5=D;11 2541 41@1C =5=1CD;1 3181H1 
H17:1CD8@141@5A=D;112541C5AB52DC	)5A=D;11254141@1C25AD@1 
@5A=D;11;1B1A1C1D81DB	,525A;1B3181H1H17:1CD8@14125414571 
@5A=D;11 ;1B1A 1;1 49@1CD;1 4571 1A18 B91A @1CD H17 C1; 
C5A1CDA	 )5=1CD1 99 49B52DC -*+01)+ 1. @5A81C9;1 $0%$4 
	 
41@D B525A;1B 3181H1 H17 :1CD8 @141 @5A=D;11 81DB 1;1 
49@1CD;145711A18H17C5A1CDA	)5=1CD19949B52DC-*+01)+ 
0.01. @5A81C9;1 $0%$4 
		 )5=1CD1 3181H1 @141 @5A=D;11 
2541 C941; B5=21A17 =519;1 =5=99;9 ;5C5A1CDA1 B5BD19 4571 
8D;D=8D;D= @5=1CD1	 
Kata Kunci 
• partikel 
• gelombang 
Gambar 6.2 
Pemantulan teratur
Contoh 6.1 
5B1ABD4DC
41@1C4931A941A9 
110 Mudah dan Aktif Belajar Fisika untuk Kelas X 
Aktivitas Fisika 6.1 
karton 
sinar 
pantul 
pointer 
inframerah 
sinar datang 
2. Hukum Pemantulan 
#9;1@141.6,8,6$5,5,.$
@A?B5B@5=1CD1@14135A=941C1A 
491;D;1 B531A1 219; 41 41@1C =55=D;1 ;5B9=@D1 218F1 
1	 BD4DC 41C17 B1=1 4571 BD4DC @1CD 
2	 B91A 41C17 71A9B ?A=1 41 B91A @1CD C5A5C1; @141 B1CD 29417 
41C1A	 )5AH1C11 49;51 4571 !D;D= )5=1CD1	 
3. Pemantulan pada Cermin 
5A=914118@5A=D;11H17=1=@D=5=1CD;1529841A9 
3181H1 H17 =57519H1	 )5A=D;11 B5@5AC9 9CD 41@1C 25AD@1 ?71= 
H17 497?B?; B589771 =57;91@ 1C1D ;131 H17 491@9B9 ?71= =9B1 
H1 491@9B9 *)$* .(/ 
Gambar 6.3 
Hukum Pemantulan. Sudut 
datang ( i ) sama dengan sudut 
pantul ( r ) 
sinar 
datang 
garis 
normal sinar 
pantul 
 i  r 
Pemantulan pada Cermin Datar 
Tujuan Percobaan 
Mengamati pemantulan pada cermin datar. 
Alat-Alat Percobaan 
Sediakanlah sumber cahaya, cermin datar, penggaris, alat tulis, dan selembar karton. 
Langkah-Langkah Percobaan 
1. Letakkan sumber cahaya, cermin 
datar, dan karton, seperti pada gambar 
berikut. 
2. Buatlah garis normal pada permuka-an 
cermin datar, titik di mana sinar 
akan dipantulkan (garis normal 
tegak lurus terhadap permukaan 
cermin datar). 
3. Gambarkan sinar yang jatuh pada permukaan cermin. Sinar ini disebut sinar 
datang. Gambarkan pula sinar yang meninggalkan permukaan cermin. Sinar 
ini disebut sinar pantul. 
4. Ukurlah sudut antara sinar datang dan garis normal. Sudut ini disebut sudut 
datang. Ukur juga sudut antara sinar pantul dan garis normal. Sudut ini 
disebut sudut pantul. Lakukan kegiatan ini tidak kurang dari lima kali. 
5. Apa yang dapat Anda simpulkan dari kegiatan ini? 
A 
P r ' 
O 
r i 1 1 
B 
r 
40° 
N 
D12D1835A=949BDBDB5@5AC9@14171=21A25A9;DC	 
#9;1B91A41C17@14135A=9=5=99;9BD4DC 
41C17JC5CD;11A18B91A@1CDBD4DC 
@1CD?5835A=9	 
$9$% 
9C9C9;14118BD4DC41C17J	 
5A41B1A;18D;D=@5=1CD1.=1;1.
J	 

P 
BAO 
NAO 6.JLJJ 
5B1ABD4DC.41@1C4931A941A9 

r ’
P 
AOB
J
r ’JJ
J 

r ’
JLJLJJ 
5B1ABD4DC
41@1C4931A941A9 

r ’ 1 
i J 
1 
i JL
r ’JLJJ 
1 
i =5AD@1;1BD4DC41C17C5A8141@35A=9
P1 
1 
S S' 
bayangan 
P2 
benda 
2 
Gambar 6.4 
Pembentukan bayangan pada 
cermin datar 
Cahaya dan Optika 111 
5A41B1A;18D;D=@5=1CD149C9C9;25A1;D 
B' 
B 
benda bayangan 
D 
A C 
s0 s' 
1 
i  1 
r 
1 
r 
J 
#1491A18B91A@1CD?5835A=9=5=25CD;BD4DCJC5A8141@71A9B?A=1	 
a. Pemantulan pada Cermin Datar 
@1 H17 41 981C @141 35A=9 41C1A ;5C9;1 41 25A49A9 49 45@1 
35A=941C1AC5AB52DC)14135A=9C5A981C14121H17141	1719=11 
B961C 21H171 H17 C5A25CD; @141 35A=9 41C1A 
)5A81C9;1$0%$4
	-9C9;,=5AD@1;121H17141A9C9C9;,	41 
@D@A?B5B@5=25CD;121H171@14135A=941C1A14118B52171925A9;DC
,91A41C17,)
B91A
:1CD8@14135A=941C1A4571BD4DC41C17 
1  ;5=D491 B91A 99 49@1CD;1	 )5A81C9;1 :11 B91A
,91A 41C17 ,)
 B91A 
 :1CD8 @141 35A=9 4571 BD4DC 41C17 
2  ;5=D491 B91A 99 49@1CD;1	 )5A81C9;1 :11 B91A 
	 
	 )5A@1:171 B91A @1CD
41 B91A @1CD 
 49 251;17 35A=9 
49D;9B;1 4571 71A9B C5A@DCDB@DCDB 41 25A@?C?71 49 C9C9;  
#149 5C1; 21H171 C9C9;  14118  H17 4925CD; 41A9 @5A@?C?71 
@5A@1:171 4D1 B91A @1CD	 
57131A1H17B1=121H17125414D149=5B941C97149=5B9 
41@1C C5A25CD; ?58 35A=9 41C1A	 )A?B5B @5=25CD;1 21H171H1 B1=1 
B5@5AC9 @141 2541 C9C9;	 !1 H17 C5A@5C97 14118 411= B5C91@ @A?B5B 
@5=25CD;1 21H171 8D;D= @5=1CD1 B51D 25A1;D	 
)5A81C9;1 $0%$4
25A9;DC	 
.CD;2541H172D;125AD@1C9C9;1C1D71A9B411;1=541@1C 
;1 218F1 D;DA1 21H171 2541 @5AB9B B1=1 4571 D;DA1 2541H1	 
541 41 21H171 81H1 25A2541 411= 81 1A18 ;9A9 41 ;11H1	 
)5A81C9;1 $0%$4 

	 1791 ;9A9 2541 =5:149 21791 ;11 
21H171 41 B5219;H1	 )5A9BC9F1 99 49B52DC @5=219;1 B9B9 )0.) 
+2./,+ (58 ;1A51 141H1 @5=219;1 B9B9 99 CD9B1 H17 8541; 
492131 =51D9 35A=9 @5D9B1 8DAD6H1 81ADB 49219;	 
5A41B1A;1 21H171 2541 @141 35A=9 41C1A 41@1C 49B9=@D;1 
218F1 B961C 21H171 2541 H17 4925CD; ?58 35A=9 41C1A 14118 
B521719 25A9;DC 
K =1H1 
K D;DA1 B1=1 25B1A 4571 D;DA1 2541 
K C571; 
K :1A1; 2541 C5A8141@ 35A=9 B1=1 4571 :1A1; 21H171 C5A8141@ 
35A=9	 
Gambar 6.5 
Ukuran benda persis sama dengan 
ukuran bayangan 
Gambar 6.6 
Ketika bercermin, posisi kiri benda 
menjadi posisi kanan bayangan 
mata 
pengamat
$:$1*$1 1:$6$ '$1 %$:$1*$1 0$:$ 
1H171H1C11411821H171H17C5A25CD;41A9@5A@?C?7117 
BD7 B91AB91A 3181H1 B5417;1 21H171 =1H1 14118 21H171 H17 
4981B9;141A9@5A@?C?71@5A@1:171B91AB91A3181H1	,5217193?C?8 
21H171 H17 4981B9;1 @141 35A=9 41C1A =5AD@1;1 21H171 =1H1 
;1A51 21H171 C5AB52DC =5AD@1;1 @5A@?C?71 17BD7 41A9 
@5A@1:171 B91AB91A 3181H1	 41@D 3?C?8 21H171 H1C1 C5A:149 
@141 21H171 H17 4981B9;1 ?58 @A?H5;C?A @141 1H1A	 
!9CD7@1:17=99=D=BD1CD35A=9H17492DCD8;1171AB5?A17@51A9141C 
41@1C=5981CB5DAD8CD2D8H1H17C9779H1%=5C5A	 
$9$% 
)5A81C9;171=21A25A9;DC	 
G 
cermin 
B 
$5C5A171 
+ 
:D=18 21H171 
  BD4DC 1C1A1 4D1 2D18 35A=9 
benda 
112 Mudah dan Aktif Belajar Fisika untuk Kelas X 
(58;1A51B91A@1CDB1=14571 
B91A41C17=1;1
#149 DCD; 41@1C =5981C 21H171 
B5DAD8 CD2D8 49@5AD;1 @1:17 
35A=9 41C1A =99=1
41A9 C9779 
CD2D8B5B5?A17	 
	 70/$+%$:$1*$12/(+'7$%7$+(40,1'$6$4 
)5A81C9;1 $0%$4 
 :9;1 B52D18 2541 25A141 49 45@1 4D1 
2D1835A=9H17=5=25CD;BD4DC B1CDB1=1191;1C5A25CD; 
B5:D=18 21H171	 #D=18 21H171 25A71CD7 @141 25A1@1 25B1A 
BD4DC 	5A41B1A;181B95;B@5A9=5:D=1821H171H174925CD; 
?584D12D1835A=9H17=5=25CD;BD4DC 14118B52171925A9;DC	 
J 
+ L
,52D182541C5A5C1;4945@1
2D1835A=941C1AH17=5=25CD;BD4DCJ	 
!9CD7:D=1821H171H17C5A25CD;	 
$9$% 
9;5C18D9 
 J 
+  
 
 
 
360 
1 
+ 
 
J 
L
J 
+ L
#149	:D=1821H171H17C5A25CD;2D18	 
L
Contoh 6.3 
F 
H 
E 
A D C 
Gambar 6.7 
Benda yang diletakkan di antara dua 
buah cermin datar dan membentuk 
sudut 90° akan menghasilkan 3 buah 
bayangan. 
cermin I 
cermin 
II 
bayangan 
bayangan bayangan 
Contoh 6.2
R 
f 
P F 
f = jarak fokus 
R = kelengkungan cermin 
Gambar 6.8 
Bagian-bagian cermin cekung 
B 
O 
a) 
c) b) 
P 
F 
B III II I 
P F 
Cahaya dan Optika 113 
O 
Gambar 6.9 
Sinar istimewa pada cermin 
cekung 
Gambar 6.10 
Pembentukan bayangan di ruang III 
AB pada cermin cekung 
O 
B' 
A' 
A 
III II I 
A' 
P A O 
Gambar 6.11 
Gambar bayangan jika letak bendanya di 
ruang II 
B 
III II I 
Gambar 6.12 
Gambar bayangan jika bendanya di 
ruang I 
B' 
5A41B1A;1 $0%$4 
$0%$4 
 41 $0%$4 
	 41@1C 
49B9=@D;1 218F1 
1 :9;1 2541 @141 AD17  =1;1 21H171 H17 4981B9;1 14118 
=1H1 C571; 41 49@5A25B1A 
2 :9;1254125A14149AD17=1;121H171H174981B9;114118 
H1C1 49 AD17  C5A219; 41 49@5A25B1A 
3 :9;1 2541 25A141 @141 AD17  =1;1 21H171 H17 4981B9;1 
14118 H1C1 49 AD17  C5A219; 41 49@5A25B1A	 
B' 
B 
F 
O 
P F A A' 
S S' 
b. Pemantulan pada Cermin Cekung 
5A=9 35;D7 14118 35A=9 H17 =5=99;9 @5A=D;11 35;D7	 
5A=9 35;D7 25AB961C ;?E5A75 H19CD 25AB961C =57D=@D;1 B91A	 
179121791 35A=9 35;D7 C1=@1; B5@5AC9 @141 $0%$4 
	 
 (0%(167.$1 %$:$1*$1 2/(+ (40,1 (.71* 
%5C1;41B961C21H171H174925CD;?5835A=935;D725A71CD7 
@1415C1;2541	,52D182541H17495C1;;14945@1B52D1835A=9 
35;D7 1;1 =5=99;9 21H171 4571 B961CB961C C5AC5CD	 )5A81C9;1 
$0%$4 
 B961CB961C 35A=9 35;D7 49 1C1A1H1 
1 ,91A 41C17 H17 B5:1:1A BD=2D DC1=1 49@1CD;1 =51D9 C9C9; 
6?;DB DC1=1	 
2 ,91A 41C17 H17 =51D9 C9C9; 6?;DB DC1=1 49@1CD;1 B5:1:1A 
4571 BD=2D DC1=1	 
3 ,91A 41C17 H17 =51D9 C9C9; @DB1C ;557;D71 35A=9 1;1 
49@1CD;1 ;5=219 =51D9 9C1B1 H17 B1=1	 
1H171B52D182541?5835A=935;D741@1C49C5CD;14571 
31A1 =5771=21A;1 
 41A9  B91A 9BC9=5F1 @141 35A=9 35;D7	 1A1 
=5D;9B 21H171 2541 ?58 35A=9 35;D7 14118 B521719 25A9;DC	 
)5A81C9;1 $0%$4 
	 +$(% -.0* 35A=9 35;D7 4971=21A 
57;1@ 4571 2179121791H1	 +$(% (!1 71A9B  4971=21A 
DCD; =51=217;1 C9779 2541	 41@D 71A9B  C941; @5AD C5A1D 
C9779	 +$(% (0$ 71=21A;1 B91A 9BC9=5F1L
+$(% (*-0 
71=21A;1 B91A 9BC9=5F1L
	 +$(% ()* C9C9; H17 =5AD@1;1 
@5A@?C?71 1C1A1 B91A @1CDL
41 B91A @1CDL
 4925A9 1=1 	 
-9C9; 99 =5AD@1;1 21H171 41A9 C9C9;  $5=D491 71A9B C571; DADB 
BD=2D DC1=1 49C1A9; 41A9 C9C9;  ;5 1A18 BD=2D DC1=1	 -9C9; 99 4925A9 
1=1H17=5AD@1;121H17141A9C9C9;B589771=5AD@1;1 
21H171 41A9 71A9B
7%71*$1 $16$4$ -$4$. )2.75 '$1 -$4,-$4, .(/(1*.71*$1 (40,1 
!D2D71 1C1A1 :1A1; 6?;DB 41 :1A9:1A9 ;557;D71 35A=9 
41@1C 4931A9 4571 @5AC??71 $0%$4 

	 
)14171=21AC5AB52DCC1=@1;218F1B91AB5:1:1ABD=2DDC1=141C17 
;5 @5A=D;11 35A=9 35;D7 ;5=D491 49@1CD;1 =51D9 C9C9; 6?;DB	 
,91AB91A 99 =579;DC9 8D;D= @5=1CD1 H19CD BD4DC 41C17 B1=1 
4571 BD4DC @1CD	 (58 ;1A51 9CD B579C971  =5AD@1;1 B579C971 
B1=1 ;1;9 B9B9 
 B9B9 #9;1 B91A 41C17 45;1C B5;19 4571 BD=2D 
DC1=1  41@1C 491771@ B1=1 4571  B589771  
  1A9 B99 
49@5A?58218F1
#1C1D 
 
// //  
# 
  =1;1 
Gambar 6.13 
Hubungan antara fokus dan jari-jari 
cermin cekung 
A P 
D F 
E 
Ingatlah 
B 
114 Mudah dan Aktif Belajar Fisika untuk Kelas X 
#
$5C5A171 
#  :1A1; 6?;DB 
 
 :1A9:1A9 ;557;D71 35A=9 

  7075 3$'$ (40,1 (.71* 
,519 B531A1 75?=5CA9 5C1; 41 B961C 21H171 2541 41@1C 
49C5CD;1 B531A1 @5A89CD71 4571 @5AB1=11 B521719 25A9;DC	 
)5A81C9;1 $0%$4 
	 
)141$0%$4 
 C1=@1; 218F1  41   B5217D 
B589771 
  

 
  
//  // 

 
 
   
  
   
(58 ;1A51 
 

 
   
  
   
L 
L 
h’ s’ 
h s 
 L 
)141$0%$4
 C1=@1;218F1  41   B5217D	 
.CD;  25A1;D C1 
 % 

 
 
 / 6  
 
.CD;   25A1;D C1 
 % 

 
 
  6 / 
 
B589771 
% % % 6/ 

 
 
/ 6   6 / % / 6  
(58 ;1A51 
% / 

 
% / 
=1;1 
/  6 / 

 
/ /6  
/ / 6 
 /  6 / // 6 /
 / 6 // 
//
// 

 

 
 
L
 
Gambar 6.14 
Letak dan sifat bayangan benda pada 
cermin cekung 
P 
R 
F 
R 
f 
A 
  
O 
) 
) ) 
Keterangan: 
s = jarak benda ke cermin 
h = tinggi benda 
f = jarak fokus 
h'= tinggi bayangan 
s' = jarak bayangan ke cermin 
571 =577D1;1 @5AB1=11 35A=9 C5AB52DC 41 41@1C =5 
5CD;1 :1A1; 21H171 B52D18 2541	 41@D @5A25B1A1 21H171  
Konvensi tanda untuk pemantulan: 
K s bernilai + jika objek berada di 
depan cermin (objek maya) 
bernilai – jika objek di belakang 
cermin (objek nyata) 
K s’ bernilai + jika objek berada di 
depan cermin (objek nyata) 
bernilai – jika objek berada di 
belakang cermin (objek maya) 
K r, f bernilai + jika pusat 
kelengkungan berada di depan 
cermin (cermin cekung) 
bernilai – jika pusat kelengkungan 
berada di belakang cermin 
(cermin cembung). 
O 
f 
s' 
R 
s 
h' 
 
 
 
 
h
f 
F P 
R 
c 
O F P 
Gambar 6.16 
Sinar-sinar istimewa pada cermin 
cembung 
Cahaya dan Optika 115 
4945699B9;1 B521719 @5A214971 1C1A1 25B1A C9779 21H171 41 
25B1A C9779 2541	 ,531A1 =1C5=1C9B 41@1C 49CD9B 
/ % 

 
 
/ % 
L 
c. Pemantulan pada Cermin Cembung 
5A=935=2D71411835A=9H17=5=99;9@5A=D;1135=2D7	 
5A=9 35=2D7 25AB961C 49E5A75 H19CD 25AB961C =5=131A;1 B91A	 
179121791 35A=9 35=2D7 B5@5AC9 @141 $0%$4
(0%(167.$1%$:$1*$12/(+(40,1(0%71* 
,52D18 2541 H17 495C1;;1 49 45@1 B52D18 35A=9 35=2D7 =5 
=99;921H1714571B961CB961CC5AC5CD	1H171B52D182541?5835A=9 
35=2D741@1C49C5CD;1457131A1=5771=21A;1
41A9B91A9BC9=5F1 
@14135A=935=2D7	)5A81C9;1$0%$4

	)141$0%$4

C5A981C 
1 B91A 41C17 H17 B5:1:1A BD=2D DC1=1 49@1CD;1 B51;11;1 
41C17 41A9 C9C9; 6?;DB 
2 B91A 41C17 H17 =5D:D C9C9; 6?;DB 49@1CD;1 B5:1:1A 4571 
BD=2D DC1=1 
3 B91A 41C17 H17 =5D:D C9C9; @DB1C ;557;D71 35A=9 49@1 
CD;1 ;5=219 =51D9 9C1B1 H17 B1=1	 
1A1 =5D;9B 21H171 2541 ?58 35A=9 35=2D7 C5A981C B5@5AC9 
@141 $0%$4 
 )141 31A1 C5AB52DC B91A 9BC9=5F1 H17 497D1;1 
14118 B91A
41 B91A 	 5A41B1A;1 71=21A 21H171 C5AB52DC 41@1C 
49B9=@D;1 218F1 2541 H17 495C1;;1 49 45@1 B52D18 35A=9 35= 
2D7 B51D =5781B9;1 21H171 =1H1 C571; 41 49@5A;539	 
	  7075 3$'$ (40,1 (0%71* 
+D=DB@14135A=935=2D7B1=1B5@5AC9AD=DBH1725A1;D@141 
35A=9 35;D7 H19CD 
   
  
   
L
# 
  
% / 

 
 
% / 
SU 
O 
Gambar 6.15 
Bagian-bagian cermin cembung 
R = jari-jari kelengkungan cermin 
P = titik pusat kelengkungan cermin 
F = titik fokus cermin 
f = jarak titik fokus ke cermin 
O F P 
a 
b 
Gambar 6.17 
Lukisan pembentukan bayangan oleh 
cermin cembung 
!181 H17 @5AD 49@5A81C9;1 14118 
1 C141 :1A1; 6?;DB @141 35A=9 35=2D7 B51D 25A919 571C96	 !1 
99 49B5212;1 5C1; C9C9; 6?;DB @141 35A=9 35=2D7 C5A5C1; 49 
251;17 35A=9 
2 DCD; 2541 H1C1 49 45@1 35A=9 35=2D7 B51D C5A25CD; 
21H171=1H1	#149919B@14135A=935=2D725AC141571C96	 
21H171 =1H1	 #149 919 / @141 35A=9 35=2D7 25AC141 571C96	 
Contoh 6.4 
,52D1835A=935;D7=5=99;9:1A9:1A9;557;D71
=	,52D182541495C1;;1@141 
:1A1;
=41A935A=9C977925413=	!9CD7185C1;C977941@5A25B1A121H171	 
$9$% 
9;5C18D9

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bab 6 kls x

  • 1. Pengemudi memanfaatkan pemantulan cahaya pada cermin A. Cahaya B. Pemantulan Cahaya C. Pembiasan Cahaya D. Alat-Alat Optik Cahaya dan Optika Hasil yang harus Anda capai: menerapkan prinsip kerja alat-alat optik. Setelah mempelajari bab ini, Anda harus mampu: ,5C91@81A9=1DB91C941;1;1@5A18C5A5@1B41A93181H1 541 2541 49 B5;5997 41 41@1C C5A981C ;1A51 141H1 3181H1 181H1 :D71 H17 =5=2D1C 41 41@1C =5981C 21H171 41 49 35A=9 D7;9 41 @5A18 =5=5A81C9;1 ;131 B@9? @141 =?29 1C1D B5@541=?C?A $131B@9?@141=?2941B5@541=?C?A=5AD@1;1B52D18 35A=9 35=2D7 H17 497D1;1 @575=D49 DCD; =5981C 1D9C1B 49 251;17 =?29 1C1D B5@541 =?C?A 571 =5981C ;131 B@9? @575=D49 41@1C 25A25?; 25A85C9 1C1D =5418DD9 ;541A11 19 4571 1=1 )141 ;131 B@9? C5A:149 @5=1CD1 3181H1 B589771 41 41@1C =5981C21H17125412541H1725A1414945@1H1 1@1C;1841 =57945C969;1B9 B961CB961C 21H171 @141 35A=9 ;131 B@9? ,51935A=935=2D725A41B1A;125CD;H11414D1:59B35A=9 19H1 H19CD 35A=9 41C1A 41 35A=9 35;D7 1@1C;18 ;54D1 35A=9 99 =55ADB;1 3181H1 1719=11 B961CB961C 21H171H1 41 41@1C =55CD;1 :1F121 @5AC1H11@5AC1H11 C5AB52DC 411= 212 99 (58 ;1A51 9CD @51:1A918 212 99 4571 219; 107 • menganalisis alat-alat optik secara kualitatif dan kuantitatif; • menerapkan alat-alat optik dalam kehidupan sehari-hari. cembung kaca spion. Bab 6 Sumber: Dokumentasi Penerbit
  • 2. Tes Kompetensi Awal !(%(/700(03(/$-$4,.215(3$+$:$'$136,.$.(4-$.$1/$+52$/52$/%(4,.76'$/$0%7.7/$6,+$1
  • 3. @1@5A254111C1A121H171=1H14121H171 1719=11B961C21H171@14135A=9 @1H1749=1;BD44571@5=291B1945;B291B A. Cahaya ,19B41C5;??79B51D=5=21F141DCD;=1=@D=5=181=9 11= !1 99 49B5212;1 B19B 41 C5;??79 B51D =5=25A9 @575C18D 1 21AD B5AC1 9BCAD=5 21AD H17 =1=@D =57D7;1@ A181B91A181B91 11= B5;19@D 75:11 11= H17 B5=D1 491771@ C941; =D7;9 C5AD7;1@ 5?=51 1BCA??=9 41@1C 5298 21H1; C5AD7;1@ ;1A51 C5AB5491H1 C55B;?@ 1C1D C5A?@?7 H17 5298 219; 41A9@141 B525D=H1 $5=1:D1 41 @55=D1 411= 29??79 =?45A C941; 41@1C C5A:149 :9;1 C941; 141 =9;A?B;?@ 1719=11 11C11C ?@C9; C5AB52DC 25;5A:1 41 =1=@D=57D7;1@A181B9111=11=212991;1492181BB5:D=18 8D;D= B5AC1 @A9B9@ ?@C9;1 75?=5CA9 @5=1CD1 41 @5=291B1 H17 49C5A1@;1 411= 2525A1@1 11C ?@C9; 1. Teori-Teori tentang Cahaya 5A9;DC 1;1 49:51B;1 2525A1@1 C5?A9 C5C17 3181H1 a. Teori Partikel )141)5AC571811214;5
  • 5. B5:1A18 9B9;1 B171C 49@571AD89 ?58 @5=9;9A1 41 ;1AH1 5$$ '(9621 =5B;9@DC5A41@1CB5:D=18C?;?825B1A19H17894D@B5I1=14571 '5FC?H17=5=25A9;1;?CA92DB925B1AC5A8141@9B9;1 ;1C5C1@9 49 1C1A1 =5A5;1 141 B521791 H17 C941; B5@541@1C 4571 (9621 49 1C1A1H1 2%(46 22.( 2%(46 2:/( +4,56,$1 7:*(15 /( 2(0(4 $0(5 4$'/(: 41 '021'$//(: )141
  • 6. (9621=55A29C;1;1AH19=918@5AC1=1C5C173181H1 41 F1A1 411= %),/,-% ) .+/ 0,+/ $5A:1 9=918 99 49C5A9=1 4571 219; ?58 B5=D1 @981; ;53D19 22.( 41 7:*(15 5A5;1 ;525A1C14571(962125A;19C14571@5A3?211H17=5=2D;C9 ;1 218F1 3181H1 C5A49A9 1C1B @1AC9;5 ;539 H17 25A75A1; 5A5;1 =571771@ 218F1 3181H1 =5AD@1;1 75?=217 -5?A9 @1AC9;5 41@1C =5:51B;1 218F1 @5A1=21C1 3181H1 25AD@1 71A9B DADB H17 C941; 41@1C 49981C 41A9 251;17 B52D18 @578117 41@D75?=217B5@5AC975?=2172DH9=1B9841@1C494571AF11D@D 49 251;17 C5A41@1C @578117 )141 1214
  • 7. (9621 =55=D;1 ;?=@?B9B93181H1@DC98H17499C57A1B9;1457165?=51F1A1 .@1H1 99=5AD@1;1C9C9;1F1;1:91;8DBDBC5C173181H1H17=5:14941B1A 2179 9B9;1 =?45A (9621 C5AC1A9; =51;D;1 @57D:91 =577D1;1 @A9B=141;131 $5C9;13181H1491A18;1@141@A9B=13181H1@DC9841@1C =5=D3D;1 21H1; F1A1 B5@5AC9 E9?5C 9497? 29AD 89:1D ;D97 ?A1H5 41 =5A18 (9621 :D71 21H1; =51;D;1 5;B@5A9=5 49 11= 4571 =5491 B5@5AC9 =9H1; 19A 41 755=2D7 B12D 5A41B1A;1 H1C1 A51C9641945;B291B=DC1; Christian Huygens (1580 – 1626) Sumber: Jendela Iptek, 1997 108 Mudah dan Aktif Belajar Fisika untuk Kelas X 1719=11 B961C 5B1 35=2D7 41 5B1 35;D7 C5A8141@25A;1B3181H1H17=55F1C9H1 ,52DC;12525A1@1=1611C5B1H1741;5C18D9 Tokoh Seorang fisikawan Belanda, Christian Huygens dilahirkan di Den Haag, pada 14 April 1626. Ayahnya seorang diplomat dan sastrawan. Pada 1666, ia memberikan sumbangan penting tentang ilmu Matematika, Astronomi, Optik, dan Mekanika, yang membuat namanya terkenal sebagai ilmuwan penting di Eropa. Pada 1655, Huygens menyempurna-kan teleskopnya yang cukup kuat untuk menemukan sebuah satelit Planet Saturnus, kemudian diberi nama Titan. Pada awal 1660-an ia menemukan lensa pelihat (okuler) yang terdiri atas gabungan lensa, guna mengurangi gangguan warna yang timbul akibat penggunaan lensa-lensa non-akromatik, lensa ini masih dipakai sampai sekarang.
  • 8. 1719=11 89@?C5B9B 7:*(15 B589771 491 25A @541@1C218F13181H1=5AD@1;175?=217 @1 ;55=181 C5?A9 75?=217 H17 =5=2D1C (9621=1B98C941;B5CD:D4571C5?A99CD 5DADC 41 49 1C1A1 C5?A9 @1AC9;5 41 C5?A9 75?=217=11;18H17@197251A Gambar 6.1 Pemantulan baur Cahaya dan Optika 109 @559C91H1 (9621 =5H9=@D;1 218F1 @141 D=D=H1 3181H1 C5A49A9 1C1B B5;D=@D1 @1AC9;5 H17 49B52DC ,.-1/ )/ b. Teori Gelombang )141
  • 9. 7:*(1525ADB181=51F1-5?A9)1AC9;54571=5H1C1 ;1218F13181H1=5AD@1;175?=217H1725A75A1;4571;535@1C1 C5AC5CD 411= =549D= 5C5A 5DADC 7:*(15 C9C9;C9C9; @141 =D;1 75?=217 H17 =5A1=21C 41@1C 491771@ B521719 75?=217 21AD )141 75?=217 97;1A1 =D;1 75?=217H1 25AD@1 97;1A1 B5417;1 @141 75?=217 41C1A =D;1 75?=217H125AD@171A9BDADB -5?A975?=21741@1C=5H1;9;1218F1 1:D 3181H1 411= 19A 5298 1=21C 41A9@141 49 D41A1 571 45=9;91 =5DADC7:*(15-5?A9)1AC9;5(96217D7DA 011D@D 45=9;91C5?A9 75?=217 C941; =1=@D =5:51B;1 C5C17 @5A1=21C1 3181H1 25AD@1 71A9B DADB $55=181 99 H17 =5H5212;1 (9621 C941; B5CD:D 4571 C5?A9 75?=217 -5?A9 7:*(15 =1=@D =55=D;1 AD=DBAD=DB @5= 291B1 41 @5=1CD1 3181H1 4571 B171C =5=D1B;1 Tes Kompetensi Subbab A (4-$.$1/$+'$/$0%7.7/$6,+$1
  • 10. 5DADCC5?A9@1AC9;541C5?A975?=2171@1;18 3181H19CD (962125A@541@1C218F13181H1=5AD@1;1@1A C9;5 5A9;1 @5:51B1 =57519 C5?A9 99 4571 ;19=1C41B549A9 B. Pemantulan Cahaya 1217 9=D @575C18D1 C5C17 3181H1 H17 =5=@51:1A9 B961C B961C@5A1=21C13181H1B5@5AC9@5=1CD1@5=291B1B5AC1@A9B9@:11 H1 B91AB91A 49B52DC ,-0( $,*0. 11= ?@C9;1 75?=5CA9 3181H1 41@1C 4971=21A;1 4571 B91A 25AD@1 71A9B H17 C571; DADB 4571 =D;175?=21741C941;B5@5D8H1=5=@5A89CD7;1B961C75?=217 41A9 3181H1 C5AB52DC )5771=21A1 3181H1 B521719 B91A 25AD@1 71A9B DADB C941; 41@1C 49C5A1@;1 411= ,-0( #// )141 ?@C9;1 69B9B 3181H1 81ADB B5@5D8H1 49@1417 B521719 75?=217 ;1A51 565; 565; 9C5A65A5B9 41 496A1;B9H1 B171C 4?=91 1. Pemantulan Baur dan Pemantulan Teratur )141 D=D=H1 B5C91@ @5=D;11 2541 41@1C =5=1CD;1 3181H1 H17:1CD8@141@5A=D;112541C5AB52DC )5A=D;11254141@1C25AD@1 @5A=D;11;1B1A1C1D81DB ,525A;1B3181H1H17:1CD8@14125414571 @5A=D;11 ;1B1A 1;1 49@1CD;1 4571 1A18 B91A @1CD H17 C1; C5A1CDA )5=1CD1 99 49B52DC -*+01)+ 1. @5A81C9;1 $0%$4 41@D B525A;1B 3181H1 H17 :1CD8 @141 @5A=D;11 81DB 1;1 49@1CD;145711A18H17C5A1CDA )5=1CD19949B52DC-*+01)+ 0.01. @5A81C9;1 $0%$4 )5=1CD1 3181H1 @141 @5A=D;11 2541 C941; B5=21A17 =519;1 =5=99;9 ;5C5A1CDA1 B5BD19 4571 8D;D=8D;D= @5=1CD1 Kata Kunci • partikel • gelombang Gambar 6.2 Pemantulan teratur
  • 12. 41@1C4931A941A9 110 Mudah dan Aktif Belajar Fisika untuk Kelas X Aktivitas Fisika 6.1 karton sinar pantul pointer inframerah sinar datang 2. Hukum Pemantulan #9;1@141.6,8,6$5,5,.$ @A?B5B@5=1CD1@14135A=941C1A 491;D;1 B531A1 219; 41 41@1C =55=D;1 ;5B9=@D1 218F1 1 BD4DC 41C17 B1=1 4571 BD4DC @1CD 2 B91A 41C17 71A9B ?A=1 41 B91A @1CD C5A5C1; @141 B1CD 29417 41C1A )5AH1C11 49;51 4571 !D;D= )5=1CD1 3. Pemantulan pada Cermin 5A=914118@5A=D;11H17=1=@D=5=1CD;1529841A9 3181H1 H17 =57519H1 )5A=D;11 B5@5AC9 9CD 41@1C 25AD@1 ?71= H17 497?B?; B589771 =57;91@ 1C1D ;131 H17 491@9B9 ?71= =9B1 H1 491@9B9 *)$* .(/ Gambar 6.3 Hukum Pemantulan. Sudut datang ( i ) sama dengan sudut pantul ( r ) sinar datang garis normal sinar pantul i r Pemantulan pada Cermin Datar Tujuan Percobaan Mengamati pemantulan pada cermin datar. Alat-Alat Percobaan Sediakanlah sumber cahaya, cermin datar, penggaris, alat tulis, dan selembar karton. Langkah-Langkah Percobaan 1. Letakkan sumber cahaya, cermin datar, dan karton, seperti pada gambar berikut. 2. Buatlah garis normal pada permuka-an cermin datar, titik di mana sinar akan dipantulkan (garis normal tegak lurus terhadap permukaan cermin datar). 3. Gambarkan sinar yang jatuh pada permukaan cermin. Sinar ini disebut sinar datang. Gambarkan pula sinar yang meninggalkan permukaan cermin. Sinar ini disebut sinar pantul. 4. Ukurlah sudut antara sinar datang dan garis normal. Sudut ini disebut sudut datang. Ukur juga sudut antara sinar pantul dan garis normal. Sudut ini disebut sudut pantul. Lakukan kegiatan ini tidak kurang dari lima kali. 5. Apa yang dapat Anda simpulkan dari kegiatan ini? A P r ' O r i 1 1 B r 40° N D12D1835A=949BDBDB5@5AC9@14171=21A25A9;DC #9;1B91A41C17@14135A=9=5=99;9BD4DC 41C17JC5CD;11A18B91A@1CDBD4DC @1CD?5835A=9 $9$% 9C9C9;14118BD4DC41C17J 5A41B1A;18D;D=@5=1CD1.=1;1. J P BAO NAO 6.JLJJ 5B1ABD4DC.41@1C4931A941A9 r ’ P AOB
  • 16. 41@1C4931A941A9 r ’ 1 i J 1 i JL r ’JLJJ 1 i =5AD@1;1BD4DC41C17C5A8141@35A=9
  • 17. P1 1 S S' bayangan P2 benda 2 Gambar 6.4 Pembentukan bayangan pada cermin datar Cahaya dan Optika 111 5A41B1A;18D;D=@5=1CD149C9C9;25A1;D B' B benda bayangan D A C s0 s' 1 i 1 r 1 r J #1491A18B91A@1CD?5835A=9=5=25CD;BD4DCJC5A8141@71A9B?A=1 a. Pemantulan pada Cermin Datar @1 H17 41 981C @141 35A=9 41C1A ;5C9;1 41 25A49A9 49 45@1 35A=941C1AC5AB52DC)14135A=9C5A981C14121H17141 1719=11 B961C 21H171 H17 C5A25CD; @141 35A=9 41C1A )5A81C9;1$0%$4 -9C9;,=5AD@1;121H17141A9C9C9;, 41 @D@A?B5B@5=25CD;121H171@14135A=941C1A14118B52171925A9;DC
  • 19. B91A
  • 20. :1CD8@14135A=941C1A4571BD4DC41C17 1 ;5=D491 B91A 99 49@1CD;1 )5A81C9;1 :11 B91A
  • 21. ,91A 41C17 ,) B91A :1CD8 @141 35A=9 4571 BD4DC 41C17 2 ;5=D491 B91A 99 49@1CD;1 )5A81C9;1 :11 B91A )5A@1:171 B91A @1CD
  • 22. 41 B91A @1CD 49 251;17 35A=9 49D;9B;1 4571 71A9B C5A@DCDB@DCDB 41 25A@?C?71 49 C9C9; #149 5C1; 21H171 C9C9; 14118 H17 4925CD; 41A9 @5A@?C?71 @5A@1:171 4D1 B91A @1CD 57131A1H17B1=121H17125414D149=5B941C97149=5B9 41@1C C5A25CD; ?58 35A=9 41C1A )A?B5B @5=25CD;1 21H171H1 B1=1 B5@5AC9 @141 2541 C9C9; !1 H17 C5A@5C97 14118 411= B5C91@ @A?B5B @5=25CD;1 21H171 8D;D= @5=1CD1 B51D 25A1;D )5A81C9;1 $0%$4
  • 23. 25A9;DC .CD;2541H172D;125AD@1C9C9;1C1D71A9B411;1=541@1C ;1 218F1 D;DA1 21H171 2541 @5AB9B B1=1 4571 D;DA1 2541H1 541 41 21H171 81H1 25A2541 411= 81 1A18 ;9A9 41 ;11H1 )5A81C9;1 $0%$4 1791 ;9A9 2541 =5:149 21791 ;11 21H171 41 B5219;H1 )5A9BC9F1 99 49B52DC @5=219;1 B9B9 )0.) +2./,+ (58 ;1A51 141H1 @5=219;1 B9B9 99 CD9B1 H17 8541; 492131 =51D9 35A=9 @5D9B1 8DAD6H1 81ADB 49219; 5A41B1A;1 21H171 2541 @141 35A=9 41C1A 41@1C 49B9=@D;1 218F1 B961C 21H171 2541 H17 4925CD; ?58 35A=9 41C1A 14118 B521719 25A9;DC K =1H1 K D;DA1 B1=1 25B1A 4571 D;DA1 2541 K C571; K :1A1; 2541 C5A8141@ 35A=9 B1=1 4571 :1A1; 21H171 C5A8141@ 35A=9 Gambar 6.5 Ukuran benda persis sama dengan ukuran bayangan Gambar 6.6 Ketika bercermin, posisi kiri benda menjadi posisi kanan bayangan mata pengamat
  • 24. $:$1*$1 1:$6$ '$1 %$:$1*$1 0$:$ 1H171H1C11411821H171H17C5A25CD;41A9@5A@?C?7117 BD7 B91AB91A 3181H1 B5417;1 21H171 =1H1 14118 21H171 H17 4981B9;141A9@5A@?C?71@5A@1:171B91AB91A3181H1 ,5217193?C?8 21H171 H17 4981B9;1 @141 35A=9 41C1A =5AD@1;1 21H171 =1H1 ;1A51 21H171 C5AB52DC =5AD@1;1 @5A@?C?71 17BD7 41A9 @5A@1:171 B91AB91A 3181H1 41@D 3?C?8 21H171 H1C1 C5A:149 @141 21H171 H17 4981B9;1 ?58 @A?H5;C?A @141 1H1A !9CD7@1:17=99=D=BD1CD35A=9H17492DCD8;1171AB5?A17@51A9141C 41@1C=5981CB5DAD8CD2D8H1H17C9779H1%=5C5A $9$% )5A81C9;171=21A25A9;DC G cermin B $5C5A171 + :D=18 21H171 BD4DC 1C1A1 4D1 2D18 35A=9 benda 112 Mudah dan Aktif Belajar Fisika untuk Kelas X (58;1A51B91A@1CDB1=14571 B91A41C17=1;1
  • 25. #149 DCD; 41@1C =5981C 21H171 B5DAD8 CD2D8 49@5AD;1 @1:17 35A=9 41C1A =99=1
  • 26. 41A9 C9779 CD2D8B5B5?A17 70/$+%$:$1*$12/(+'7$%7$+(40,1'$6$4 )5A81C9;1 $0%$4 :9;1 B52D18 2541 25A141 49 45@1 4D1 2D1835A=9H17=5=25CD;BD4DC B1CDB1=1191;1C5A25CD; B5:D=18 21H171 #D=18 21H171 25A71CD7 @141 25A1@1 25B1A BD4DC 5A41B1A;181B95;B@5A9=5:D=1821H171H174925CD; ?584D12D1835A=9H17=5=25CD;BD4DC 14118B52171925A9;DC J + L
  • 28. J + L
  • 30. Contoh 6.3 F H E A D C Gambar 6.7 Benda yang diletakkan di antara dua buah cermin datar dan membentuk sudut 90° akan menghasilkan 3 buah bayangan. cermin I cermin II bayangan bayangan bayangan Contoh 6.2
  • 31. R f P F f = jarak fokus R = kelengkungan cermin Gambar 6.8 Bagian-bagian cermin cekung B O a) c) b) P F B III II I P F Cahaya dan Optika 113 O Gambar 6.9 Sinar istimewa pada cermin cekung Gambar 6.10 Pembentukan bayangan di ruang III AB pada cermin cekung O B' A' A III II I A' P A O Gambar 6.11 Gambar bayangan jika letak bendanya di ruang II B III II I Gambar 6.12 Gambar bayangan jika bendanya di ruang I B' 5A41B1A;1 $0%$4 $0%$4 41 $0%$4 41@1C 49B9=@D;1 218F1 1 :9;1 2541 @141 AD17 =1;1 21H171 H17 4981B9;1 14118 =1H1 C571; 41 49@5A25B1A 2 :9;1254125A14149AD17=1;121H171H174981B9;114118 H1C1 49 AD17 C5A219; 41 49@5A25B1A 3 :9;1 2541 25A141 @141 AD17 =1;1 21H171 H17 4981B9;1 14118 H1C1 49 AD17 C5A219; 41 49@5A25B1A B' B F O P F A A' S S' b. Pemantulan pada Cermin Cekung 5A=9 35;D7 14118 35A=9 H17 =5=99;9 @5A=D;11 35;D7 5A=9 35;D7 25AB961C ;?E5A75 H19CD 25AB961C =57D=@D;1 B91A 179121791 35A=9 35;D7 C1=@1; B5@5AC9 @141 $0%$4 (0%(167.$1 %$:$1*$1 2/(+ (40,1 (.71* %5C1;41B961C21H171H174925CD;?5835A=935;D725A71CD7 @1415C1;2541 ,52D182541H17495C1;;14945@1B52D1835A=9 35;D7 1;1 =5=99;9 21H171 4571 B961CB961C C5AC5CD )5A81C9;1 $0%$4 B961CB961C 35A=9 35;D7 49 1C1A1H1 1 ,91A 41C17 H17 B5:1:1A BD=2D DC1=1 49@1CD;1 =51D9 C9C9; 6?;DB DC1=1 2 ,91A 41C17 H17 =51D9 C9C9; 6?;DB DC1=1 49@1CD;1 B5:1:1A 4571 BD=2D DC1=1 3 ,91A 41C17 H17 =51D9 C9C9; @DB1C ;557;D71 35A=9 1;1 49@1CD;1 ;5=219 =51D9 9C1B1 H17 B1=1 1H171B52D182541?5835A=935;D741@1C49C5CD;14571 31A1 =5771=21A;1 41A9 B91A 9BC9=5F1 @141 35A=9 35;D7 1A1 =5D;9B 21H171 2541 ?58 35A=9 35;D7 14118 B521719 25A9;DC )5A81C9;1 $0%$4 +$(% -.0* 35A=9 35;D7 4971=21A 57;1@ 4571 2179121791H1 +$(% (!1 71A9B 4971=21A DCD; =51=217;1 C9779 2541 41@D 71A9B C941; @5AD C5A1D C9779 +$(% (0$ 71=21A;1 B91A 9BC9=5F1L
  • 32. +$(% (*-0 71=21A;1 B91A 9BC9=5F1L +$(% ()* C9C9; H17 =5AD@1;1 @5A@?C?71 1C1A1 B91A @1CDL
  • 33. 41 B91A @1CDL 4925A9 1=1 -9C9; 99 =5AD@1;1 21H171 41A9 C9C9; $5=D491 71A9B C571; DADB BD=2D DC1=1 49C1A9; 41A9 C9C9; ;5 1A18 BD=2D DC1=1 -9C9; 99 4925A9 1=1H17=5AD@1;121H17141A9C9C9;B589771=5AD@1;1 21H171 41A9 71A9B
  • 34. 7%71*$1 $16$4$ -$4$. )2.75 '$1 -$4,-$4, .(/(1*.71*$1 (40,1 !D2D71 1C1A1 :1A1; 6?;DB 41 :1A9:1A9 ;557;D71 35A=9 41@1C 4931A9 4571 @5AC??71 $0%$4 )14171=21AC5AB52DCC1=@1;218F1B91AB5:1:1ABD=2DDC1=141C17 ;5 @5A=D;11 35A=9 35;D7 ;5=D491 49@1CD;1 =51D9 C9C9; 6?;DB ,91AB91A 99 =579;DC9 8D;D= @5=1CD1 H19CD BD4DC 41C17 B1=1 4571 BD4DC @1CD (58 ;1A51 9CD B579C971 =5AD@1;1 B579C971 B1=1 ;1;9 B9B9 B9B9 #9;1 B91A 41C17 45;1C B5;19 4571 BD=2D DC1=1 41@1C 491771@ B1=1 4571 B589771 1A9 B99 49@5A?58218F1 #1C1D // // # =1;1 Gambar 6.13 Hubungan antara fokus dan jari-jari cermin cekung A P D F E Ingatlah B 114 Mudah dan Aktif Belajar Fisika untuk Kelas X #
  • 35. $5C5A171 # :1A1; 6?;DB :1A9:1A9 ;557;D71 35A=9 7075 3$'$ (40,1 (.71* ,519 B531A1 75?=5CA9 5C1; 41 B961C 21H171 2541 41@1C 49C5CD;1 B531A1 @5A89CD71 4571 @5AB1=11 B521719 25A9;DC )5A81C9;1 $0%$4 )141$0%$4 C1=@1; 218F1 41 B5217D B589771 // // (58 ;1A51 L L h’ s’ h s L )141$0%$4 C1=@1;218F1 41 B5217D .CD; 25A1;D C1 % / 6 .CD; 25A1;D C1 % 6 / B589771 % % % 6/ / 6 6 / % / 6 (58 ;1A51 % / % / =1;1 / 6 / / /6 / / 6 / 6 / // 6 / / 6 // // // L Gambar 6.14 Letak dan sifat bayangan benda pada cermin cekung P R F R f A O ) ) ) Keterangan: s = jarak benda ke cermin h = tinggi benda f = jarak fokus h'= tinggi bayangan s' = jarak bayangan ke cermin 571 =577D1;1 @5AB1=11 35A=9 C5AB52DC 41 41@1C =5 5CD;1 :1A1; 21H171 B52D18 2541 41@D @5A25B1A1 21H171 Konvensi tanda untuk pemantulan: K s bernilai + jika objek berada di depan cermin (objek maya) bernilai – jika objek di belakang cermin (objek nyata) K s’ bernilai + jika objek berada di depan cermin (objek nyata) bernilai – jika objek berada di belakang cermin (objek maya) K r, f bernilai + jika pusat kelengkungan berada di depan cermin (cermin cekung) bernilai – jika pusat kelengkungan berada di belakang cermin (cermin cembung). O f s' R s h' h
  • 36. f F P R c O F P Gambar 6.16 Sinar-sinar istimewa pada cermin cembung Cahaya dan Optika 115 4945699B9;1 B521719 @5A214971 1C1A1 25B1A C9779 21H171 41 25B1A C9779 2541 ,531A1 =1C5=1C9B 41@1C 49CD9B / % / % L c. Pemantulan pada Cermin Cembung 5A=935=2D71411835A=9H17=5=99;9@5A=D;1135=2D7 5A=9 35=2D7 25AB961C 49E5A75 H19CD 25AB961C =5=131A;1 B91A 179121791 35A=9 35=2D7 B5@5AC9 @141 $0%$4
  • 37. (0%(167.$1%$:$1*$12/(+(40,1(0%71* ,52D18 2541 H17 495C1;;1 49 45@1 B52D18 35A=9 35=2D7 =5 =99;921H1714571B961CB961CC5AC5CD 1H171B52D182541?5835A=9 35=2D741@1C49C5CD;1457131A1=5771=21A;1 41A9B91A9BC9=5F1 @14135A=935=2D7 )5A81C9;1$0%$4 )141$0%$4 C5A981C 1 B91A 41C17 H17 B5:1:1A BD=2D DC1=1 49@1CD;1 B51;11;1 41C17 41A9 C9C9; 6?;DB 2 B91A 41C17 H17 =5D:D C9C9; 6?;DB 49@1CD;1 B5:1:1A 4571 BD=2D DC1=1 3 B91A 41C17 H17 =5D:D C9C9; @DB1C ;557;D71 35A=9 49@1 CD;1 ;5=219 =51D9 9C1B1 H17 B1=1 1A1 =5D;9B 21H171 2541 ?58 35A=9 35=2D7 C5A981C B5@5AC9 @141 $0%$4 )141 31A1 C5AB52DC B91A 9BC9=5F1 H17 497D1;1 14118 B91A
  • 38. 41 B91A 5A41B1A;1 71=21A 21H171 C5AB52DC 41@1C 49B9=@D;1 218F1 2541 H17 495C1;;1 49 45@1 B52D18 35A=9 35= 2D7 B51D =5781B9;1 21H171 =1H1 C571; 41 49@5A;539 7075 3$'$ (40,1 (0%71* +D=DB@14135A=935=2D7B1=1B5@5AC9AD=DBH1725A1;D@141 35A=9 35;D7 H19CD L
  • 39. # % / % / SU O Gambar 6.15 Bagian-bagian cermin cembung R = jari-jari kelengkungan cermin P = titik pusat kelengkungan cermin F = titik fokus cermin f = jarak titik fokus ke cermin O F P a b Gambar 6.17 Lukisan pembentukan bayangan oleh cermin cembung !181 H17 @5AD 49@5A81C9;1 14118 1 C141 :1A1; 6?;DB @141 35A=9 35=2D7 B51D 25A919 571C96 !1 99 49B5212;1 5C1; C9C9; 6?;DB @141 35A=9 35=2D7 C5A5C1; 49 251;17 35A=9 2 DCD; 2541 H1C1 49 45@1 35A=9 35=2D7 B51D C5A25CD; 21H171=1H1 #149919B@14135A=935=2D725AC141571C96 21H171 =1H1 #149 919 / @141 35A=9 35=2D7 25AC141 571C96 Contoh 6.4 ,52D1835A=935;D7=5=99;9:1A9:1A9;557;D71 = ,52D182541495C1;;1@141 :1A1;
  • 42. 3= 116 Mudah dan Aktif Belajar Fisika untuk Kelas X #
  • 43. = p' s s' p benda / % % % / % % % bayangan P /
  • 44. = =
  • 49. / / #
  • 52. /
  • 56. L /
  • 58. L /
  • 60. / / =
  • 63. 3=41@5A25B1A1H1 ;19 ,52D182541495C1;;13=4945@135A=935=2D7H1725A:1A9:1A93= 1 9=115C1;21H171 2 5A1@1@5A25B1A1H1 3 %D;9B:11H1B91A@141@5=25CD;121H171 $9$% 9;5C18D9 /3= L3=
  • 65. # L 1
  • 68. 6 / /
  • 71. L
  • 72. /
  • 75. L /
  • 76. L / /L
  • 77. 3= 2 L
  • 78. / /
  • 80. ;19B961C21H171C571;=1H14149@5A;539 3 • optika geometri • optika fisis • pemantulan baur • pemantulan halus • bayangan nyata • bayangan maya • titik fokus utama • pusat kelengkungan Tes Kompetensi Subbab B (4-$.$1/$+'$/$0%7.7/$6,+$1
  • 81. ,525A;1BB91A41C17:1CD8@141B52D18@5A=D;11 35A=94571BD4DCJ #9;149979;1B91A@1CD ?5835A=9;54D1B5:1:1A4571B91A41C1725A1@1;18 BD4DC1C1A135A=9@5AC1=14135A=9;54D1 -9712D1835A=949BDBDB5@5AC971=21A25A9;DC -5CD;11A18B91A@1CD41A935A=9C5AB52DC D1 2D18 35A=9 41C1A =5=25CD; BD4DC J ,52D18 2541 C5A5C1; 49 45@1 ;54D1 35A=9 C5AB52DC -5CD;1 :D=18 21H171 H17 C5A 25CD; ,52D182541C571;C9779H1 3=495C1;;149 45@135A=935;D725A:1A9:1A9 3=@141:1A1; 3=41A935A=9 1 -5CD;1:1A1;21H171;535A=9 2 %D;9B:1A1;H1B91A@141@5=25CD;121H171 3 -5CD;1B961CB961C21H171 30° 140° 120° cermin I cermin II cermin III
  • 82. Cahaya dan Optika 117 C. Pembiasan Cahaya 71A 41 =5=181=9 @5A9BC9F1 @5=291B1 3181H1 1;D;118 ;5791C1 25A9;DC Aktivitas Fisika 6.2 Pembiasan dan Pemantulan Tujuan Percobaan Mengamati peristiwa pembiasan dan pemantulan. Alat-Alat Percobaan 1. Baterai kering 6. Kapas 2. Pengunci kertas 7. Bohlam kecil dalam wadah 3. Pensil 8. Klip kertas 4. Obeng, gunting, dan double tape 9. Kabel 5. Aluminium foil 10. Botol air plastik Langkah-Langkah Percobaan 1. Potong bagian atas botol, kemudian menggunakan pensil lubangi botol di pinggiran botol. 2. Rekatkan aluminium foil di dalam bagian atas botol yang sudah dipotong, seperti pada gambar (b). 3. Pasangkan dua buah kabel pada bohlam kecil yang sudah ditempatkan pada wadahnya. 4. Satukan baterai secara seri, lalu rekatkan kabel ketiga pada bagian bawah baterai (kutub negatif ), seperti pada gambar (d). 5. Rekatkan satu kabel dari wadah bohlam ke bagian atas baterai (kutub positif ). 6. Masukkan kabel ke dalam lubang di pinggir botol, penuhi botol dengan kapas dan tempatkan kedua kabel dengan pengunci kertas. 7. Tempatkan wadah bohlam di atas baterai, dan tempatkan tengah-tengah bohlam tepat di bagian atas botol yang sudah diratakan aluminium foil. 8. Bengkokkan klip kertas dan tempatkan pada salah satu ujung pengunci kertas sehingga menjadi saklar senter tersebut. 9. Tekan ujung lainnya klip kertas ke pengunci kertas yang lain senter kini menyala. 10. Apa yang menyebabkan nyala filamen lampu menyebar ke depan senter? 11. Apa manfaat adanya aluminium foil pada bagian atas botol yang dipotong? Peristiwa apa yang terjadi pada aluminium foil tersebut? )5A81C9;1H111=@DB5C5AB5@5AC9@141.6,8,6$5 %97;D71 H17 =597;D@9 691=5 1=@D 14118 81=@1 D41A1 ;5=D491 3181H1 49C5ADB;1 ;5 D41A1 D1A D;1;18 3181H1H1 =5H521A @1 @5A1 ;131 @5=21C1B H17 =5=25CD; 2?1 )5A9BC9F1 H17 4911=9 3181H1 491=1;1 @5A9BC9F1 @5=291B1 */+ .#.(/ 14118 -./03 -*),(+ .% %4 (0( *)30 !+$ 0/ +0. !1 *!1* 4+$ .! )5=291B1 3181H1 C5A:149 1;921C ;535@1C1 3181H1 25A2541 @141 B5C91@ =549D= D7;9 41 @5A18 =5981C B52D18 @5B9 H17 C5A35D@ B521791 ;5 411= 19A 49 411= 751B @5A9BC9F1 9CD =5=@5A981C;1 @5=291B1 )5A81C9;1$0%$4 1791@5B9H17C5A35D@;519A;5981C1@1C18 )5A81C9;1@D1:9;14997;D7141C5A41@1C;?1=H17:5A9841B1A ;?1= C5AB52DC C5A981C 5298 417;1 )5A9BC9F1 C5AB52DC :D71 =5AD@1;1 3?C?8 @5A9BC9F1 @5=291B1 3181H1 (a) (b) (c) (d) (e) ,52D182541495C1;;14945@135A=935=2D7 B545=9;91AD@1B58977125B1A21H171H1;19 #9;121H171H17C5A25CD;C5@1CL41:1A9:1A9 ;557;D7135A=935=2D7 3=89CD7:1A1; 2541;535A=9 Gambar 6.18 Pensil seperti patah ketika tercelup ke dalam air
  • 83. 1. Indeks Bias 45;B291B41@1C49@1417B521719BD1CD;5=1=@D1=549D==5= 291B;1 =5=25?;;1 1A18 A1=21C 3181H1 #9;1 3181H1 25A75A1; 41A9 E1;D= 1C1D D41A1 ;5 =549D= 19 945;B 291BH1 49B52DC +!(/ / *10)(=549D=C5AB52DC )1415;B@5A9=5,59DB919945;B291BH17 4941@1C+
  • 84. =5AD@1;1919945;B291B=DC1;;131;1A513181H1 25A75A1; 41A9 E1;D= 1C1D D41A1 ;5 ;131 ,531A1 =1C5=1C9B 41@1C 49CD9B B521719 25A9;DC r i B 118 Mudah dan Aktif Belajar Fisika untuk Kelas X L + 2 2. Hukum Pembiasan )5=291B13181H1C941;B5=21A17C5C1@9=579;DC98D;D=8D;D=@5= 291B1 !D;D=@5=291B1@5AC1=1;1949H1C1;1?58#,//(%424'!1(//,75 189 9B9;1 25A;5217B11 5141 !1(//,75 =51;D;1 5;B@5A9=5 4571 =55F1C;1 B525A;1B B91A @141 21?; ;131 5A41B1A;1 81B9 5;B@5A9=5 H17 491;D;1H1 !1(//,75 ;5=D491 =5H1C1;1 !D;D= )5=291B1 H1H19CD-.+!+$+/+1//1!10!0+$!+/+1//1!10/!./101 %4 4+$!0+$!./101*!1*(*!1*)+*.1-(+/101(,+/0+04+$ /.+4 /* !+$+ -.+!+$+ +!(/ / (!1 *!1* 0./10 +9B9+AB9. B9 B9 . + . + $%(/ 45;B91BDC1;525A1@1549D= (',70 /1;D= .41A1 9A J C91;?8? $131 $D1AB1 $5A?1 9C1 $131@5G9 C1
  • 85. + . B9 B9 . L $5C5A171 BD4DC 41C17 . BD4DC 291B A51C96 +945;B291B 45;B 291B A51C96 BD1CD =549D= 14118 @5A214971 919 945;B 291B =DC1; 41A9 4D1 =549D= H17 25A2541 9B1H1 B525A;1B 3181H1 25A75A1; 41A9 =549D= 19A +. ;5 =549D= ;131 +( ,531A1=1C5=1C9B945;B291B19AA51C96C5A8141@=549D=;13141@1C49CD9B . ( . + ( + + Sumber: Fundamentals of Physics, 2001 Gambar 6.19 Deskripsi hukum pembiasan $5C5A171 + 945;B 291B =DC1; ;535@1C1 3181H1 49 E1;D= D41A1 2 ;535@1C1 3181H1 49 BD1CD =549D= '919 945;B 291B =DC1; 2525A1@1 =549D= 49CD:D;;1 @141 $%(/
  • 86. medium air (medium–1) medium kaca (medium–2) Gambar 6.20 Sinar yang melalui dua medium berbeda, yaitu air dan kaca. medium 1 medium 2 Gambar 6.21 Cahaya dan Optika 119 ,531A1 D=D= :9;1 3181H1 25A75A1; 41A9 =549D=
  • 89. + + + +
  • 90. B9 B9 + + . )5AB1=11 C5AB52DC 41@1C :D71 49CD9B B521719 25A9;DC + $5C5A171 +
  • 92. + 945;B 291B =DC1; =549D= +
  • 93. 945;B 291B =549D= A51C96 C5A8141@ =549D=
  • 94. BD4DC 41C17 49 =549D=
  • 95. . BD4DC 291B 49 =549D= 3. Hubungan Cepat Rambat Cahaya dan Indeks Bias Medium )5A81C9;1 $0%$4 9B1H1 BD1CD 75?=217 29417 )* 495F1C;1=51D9=549D=
  • 96. ;5=549D= H175298A1@1C ,5C518F1;CD 0 75?=217 29417 )* 25A141 @141 29417 ,+ 2 0 2 0
  • 98. 2 0 2 0
  • 99. 2 2
  • 101. L
  • 104. 9;5C18D92 # 4571#6A5;D5B941 @1:1775?=217 571 45=9;91 919 945;B 291B 41@1C 49@5A?58 :D71 41A9 @1:17 75?=217 2 12 1 n L
  • 105. B9 B9 + + . L
  • 106. (45$0$$1 ;413(45$0$$1 ; =5=99;9=1;169B9BH19CD ;535@1C1 3181H1 411= BD1CD =549D= 25A21497 C5A219; 4571 919 945;B 291BH1 1;BD4H1 :9;1 945;B 291B B5=1;9 25B1A ;535@1C1 3181H1 B5=1;9 ;539 ,521719 3?C?8 ;535@1C1 3181H1 411= =549D= ;131 5298 ;539 4921497;1 4571 ;535@1C1 3181H1 ;5C9;1 =5A1=21C 411= 19A 1B1H1 945;B 291B =DC1; ;131 5298 25B1A 41A9@141 945;B =DC1; 19A ,519 9CD 41 :D71 41@1C =5H9=@D;1 218F1 ;5C9;1 75?=217 =5A1=21C 41A9 BD1CD =549D= ;5 =549D= 19 H17 945;B 291BH125A2541@1:1775?=217 4125B1A;535@1C1275?=217 C5AB52DC 25AD218 1=D 6A5;D5B9 # 75?=217 C5AB52DC C941; 25AD218 Pembiasan cahaya melalui dua medium ) ) R S P Q 1 2 2 1
  • 107. Contoh 6.6 11=B52D185;B@5A9=5DCD;=55CD;1;535@1C13181H149411=19AB5?A17 B9BF1=55F1C;1B525A;1B3181H1;5411=19A4571BD4DC41C17J $5=D491 B9BF1=531C1CBD4DC291BH17C5A:14949411=19AC5AH1C125B1AH1 J #9;1;535@1C1 3181H149D41A1491771@M
  • 109. = B. J r 4919A B9 B9 2 M
  • 110. = B i i n1 n2 n1 n2 r n1n2 n1n2 r Contoh 6.7 + . + B9 B9
  • 111. B9 B9 (a) (b) 120 Mudah dan Aktif Belajar Fisika untuk Kelas X B9 J B9 J M
  • 112. = B M
  • 114. = B Gambar 6.22 Sinar datang dibiaskan: (a) mendekati garis normal jika n1 n2; (b) menjauhi garis normal jika n1 n2. ,55;?A9;125A1414941B1A;?1=H17411=H1= 19A + B5@5AC9C1=@1; @14171=21A49B1=@97 )141;5411=125A1@1;185C1;9;141B1A;?1=C5AB52DCC5A981C?58@571=1C 41A9@5A=D;1119A:9;1 1 9;149981C@571=1CB531A1C571;DADB 2 BD4DC1C1A1=1C14171A9B?A=1B525B1AJ $9$% 1 )5A81C9;171=21A #9;1@571=1C=5981C9;1B531A1C571;DADB1;1=5=5D89@5AB1=11 C1.B9.41C1B9 ,91A41C1741A99;1B589771 C1 B9 C1 B9 ! . . ! 1C1D + ! 1! + ! . =1;1 ;5411=19;149@5A?58H19CD
  • 115. ! 1C1D! = #149;5411=1B5=D9;1H1749981C@571=1CB531A1C571;DADB14118= 2 $5411=19;1DCD;BD4DC1C1A1=1C1@571=1C4171A9B?A=1.J 14118 1! . B9 B9J J B589771 ! ! . ! C1 C1 J = C1 C1 J #149;5411=1B5=D9;1DCD;BD4DC.J=5:149 = dasar kolam 4 m nud = 1 nair = 4 3 r d = 4 m i r d ' i ,521719 ;?B5;D5B9 41A9 !D;D= ,59DB 99 B91A 41C17 41A9 =549D=;DA17A1@1C;5=549D=5298A1@1C+
  • 116. + /+.(+!/(+ *+!(0 $./+,.*) !+'(/+.!0+$ !.*!1* )% .-0(* !1*(1.+$.-0+ + B91A1;149291B;1=5:1D8971A9B?A=1 (4+$6,.$1 $0%$4 mata pengamat
  • 117. n2 n1 (n1n2) r r r i i i 1 2 3 4 5 i 6 udara kaca i r r Tantangan untuk Anda udara plastik air Cahaya dan Optika 121 4. Sudut Kritis dan Pemantulan Sempurna 571@1 25A91 C1=@1; 25A;91D1 ;5C9;1 3181H1 :1CD8 @141 @5A=D;11H1 571@1 @141 B11C C5A9; =1C181A9 :11 A1H1 25A1B@1 C1=@1; B5@5AC9 C5A7517 19A )141 ;54D1 75:11 9B9;1 C5AB52DC 3181H1 =5711=9 @5=1CD1 B531A1 B5=@DA1 1719=11 @5=1CD1 B5=@DA1 41@1C C5A:149 )5A81C9;1 $0%$4 1=21A C5AB52DC =5D:D;;1 3181H1 25A75A1; 41A9 =549D= 5298 A1@1C;131;5=549D=;DA17A1@1CD41A11C1D41A9=549D=25A945;B 291B529825B1A;5=549D=25A945;B291B5298;539B589771B91A291BH1 =5:1D89 71A9B ?A=1 $5C9;1 BD4DC 41C17 ? BD4DC 291BH1 :D71 ? B5@5AC9 49CD:D;;1 ?58 B91A
  • 118. $5=D491 @141 B11C BD4DC 41C17 49@5A25B1A B91A B91A 41 B91A BD4DC 291B @D 25AC1=218 25B1A 1C1D B5=1;9 =5:1D89 71A9B ?A=1 )141 B11C 25B1A BD4DC 41C17 C5AC5CD H1;9 B5@5AC9 B91A 3181H1 49291B;1 J C5A8141@ 71A9B ?A=1 B589771 B91A 291BH1 B5:1:1A 4571 @5A=D;11 29417 21C1B =549D= ;131D41A1 )141 ;51411 B5@5AC9 99 BD4DC 41C17 49B52DC BD4DC ;A9C9B 571 ;1C1 19 BD4DC ;A9C9B 14118 BD4DC 41C17 ;5C9;1 B91A 41C17 49291B;1B525B1AJ #9;1BD4DC41C1749@5A25B1A179=552989BD4DC;A9C9B 3181H1 C941; 1;1 49291B;1 =519;1 49@1CD;1 B531A1 B5=@DA1 AC9H1 3181H1 C941; 1;1 ;5D1A 41A9 =549D= ;131 B5@5AC9 49CD:D;;1 ?58 B91A )5A9BC9F1 9918 H17 49B52DC @5=1CD1 B5=@DA1 5A41B1A;1 81 C5AB52DC 41@1C 49B9=@D;1 218F1 @5=1CD1 B5=@DA1 81H1 C5A:149 :9;1 =5=5D89 4D1 BH1A1C 25A9;DC 1 181H1 41C17 41A9 =549D= 5298 A1@1C ;5 =549D= ;DA17 A1@1C 2 ,D4DC 41C17 5298 25B1A 41A9@141 BD4DC ;A9C9B Gambar 6.23 Deskripsi geometri tentang sudut kritis dan pemantulan sempurna Aktivitas Fisika 6.3 Sepotong plastik transparan terapung dipermukaan air. Agar sinar datang seperti pada gambar di atas dipantulkan sempurna oleh permukaan batas plastik air. Jika indek bias plastik nk dan indek bias air na, berapa besar sudut ? Pemantulan Sempurna Tujuan Percobaan Mengamati pemantulan sempurna. Alat-Alat Percobaan Gelas minum, lilin, dan air. Langkah-Langkah Percobaan 1. Isilah gelas minum dengan air sampai hampir penuh. 2. Letakkan gelas tersebut di pinggir meja. 3. Nyalakan lilin pendek dan letakkan dekat dengan gelas. 4. Perhatikan gambar berikut. Amati dari arah yang berseberangan dengan lilin dari arah agak di bawah permukaan. 5. Apa yang dapat Anda amati? 6. Apa kesimpulan Anda dari kegiatan ini? mata pengamat )A9B9@ @5=1CD1 B5=@DA1 49=1611C;1 411= C5;??79 ;?=D9 ;1B9 H1;9 @141 B5A1C ?@C9; #. ,-0 B5@5AC9 @141 $0%$4 ,5A1C ?@C9;14118BD1CDB5A1C81DBC5A2D1C41A9@1BC9;1C1D;131H17497D1;1 DCD; =5H1DA;1 3181H1 1C1D 75?=217 55;CA?=175C9; ,5A1C ?@C9; C5A49A9 1C1B 21791 9C9 41 21791 D1A B521719 @5=2D7;DBH1 1791 9C9 C5A2D1C 41A9 ;131 H17 =5=99;9 945;B 291B C9779 41 25A;D19C1B 219;
  • 119. (a) (b) Gambar 6.24 (a) Pemantulan sempurna pada serat optik. (b) serat optik. 45;B 291B H17 C9779 1;1 =571;921C;1 BD4DC ;A9C9B ;539 B589771 B91A41C174571BD4DC41C17H17C941;C5A1D25B1A1;1=5711=9 @5=1CD1 B5=@DA1 1791 D1A H17 =5AD@1;1 @5=2D7;DB C5A2D1C 41A9 @1BC9; 1C1D =1C5A91 19 H17 25A6D7B9 =594D79 21791 9C9 (58 ;1A51 3181H1 1C1D 75?=217 55;CA?=175C9; H17 =1BD; ;5 411= B5A1C ?@C9; =5 711=9 @5=1CD1 B5=@DA1 @141 B11C ;5D1A 41A9 B5A1C ?@C9; 55A79 3181H1 C941; 21H1; H17 8917 5A41B1A;1 81 9CD :9;1 H17 49;9A9= 14118 B9H1B9H1 ;?=D9;1B9 411= 25CD; 75?=217 3181H1 @141 B11C 49C5A9=1 49 C5=@1C CD:D1 B9H1 C5AB52DC B1=@19 B531A1 DCD8 C1@1 21H1; ;589171 55A79 5A41B1A;1 @141 @A?B5B C5A:149H1 @5=1 CD1 B5=@DA1 41@1C 49C5CD;1 @D1 25B1AH1 BD4DC ;A9C9B DCD; 4D1 =549D= C5AC5CD B521719 25A9;DC )141B11CC5A:149@5=1CD1B5=@DA125A1;D@5AB1=1125A9;DC ( + Contoh 6.8 !9CD7BD4DC;A9C9B25A91H17=5=99;9945;B291B=DC1;
  • 121. +
  • 122. + B9 ( +
  • 123. 5 Pembiasan pada Kaca Plan Paralel $131 @1 @1A15 14118 B5;5@97 ;131 H17 ;54D1 B9B9 @1:17H1 492D1C B5:1:1A $131 @1 @1A15 41@1C 497D1;1 DCD; =571=1C9 :11H1B91AH17=5711=9@5=291B141DCD;=55CD;1945;B 291B ;131 C5AB52DC ,91A 41C17 41A9 D41A1 =55F19 ;131 B5C521 ! 3= ;5=D491 =5D:D =549D= D41A1 ;5=219 )141 @A?B5B C5AB52DC B5@5AC9 C1=@1; @141 $0%$4
  • 124. 41 $0%$4 591A =5711=9 @5A75B5A1 41A9 1A18 B91AB5=D1 5B1AH1@5A75B5A1B91AC5AB52DC41@1C4989CD7B52171925A9;DC 122 Mudah dan Aktif Belajar Fisika untuk Kelas X
  • 126. B9 B9 5 + 1C1D B9 ( + + L
  • 127. $5C5A171 ; BD4DC ;A9C9B 6 . ( 0 t i r 1 1 sin )5A81C9;1 ( B9 ( ( L
  • 128. Gambar 6.25 Seberkas cahaya memasuki kaca plan paralel d D B A O t r2 r1 i1 Gambar 6.26 Pergeseran arah sinar pada kaca plan paralel
  • 129. B9 B9 + . + 4571+
  • 131. N N sinar datang Cahaya dan Optika 123 ( d r 1 cos L
  • 133. ( 3?B ! ( ( . 5A41B1A;1 (45$0$$1 ; 41 (45$0$$1 ;
  • 134. 49@5A?58 ! 0 . 6 .
  • 137. 3?B B9 B589771 25B1A @5A75B5A1 B91A 0
  • 139. B9 L 3?B ! . .
  • 140. L
  • 142. BD4DC 41C17 ! C521 ;131 @1 @1A15 .
  • 143. BD4DC 291B 025B1A@5A75B5A1B91A Contoh 6.9 ,525A;1BB91A1B5A:1CD8@141@5A=D;11;131@1@1A1541@1C=5=25CD;BD4DC 41C17B525B1AJ #9;1C521;131@1@1A15
  • 145. J.
  • 146. J!
  • 147. 3= 0
  • 149. B9 L 3?B ! . .
  • 150. B9 J L J
  • 151. 3?B J #149;5C9;1=55F1C9;131@1@1A15B91A1B5A=5711=9@5A75B5A13=41A9 1A18B5=D1 6. Pembiasan pada Prisma )A9B=1=5AD@1;12541H17C5A2D1C41A9751BC5=2DB3181H1CA1B @1A1H17;54D1B9B9H14921C1B929417@5A=D;1H17A5=25CD;BD4DC C5AC5CD B1CD B1=1 19 ,D4DC C5AB52DC 491=1;1 BD4DC @5=291B B9=2? 9417 @5A=D;11 @A9B=1 25A6D7B9 B521719 29417 @5=291B )5A81C9;1:11H1B91AH17=55F1C9B52D18@A9B=1@141$0%$4 181H1 41C17 41A9 D41A1 =5D:D 29417 @5A=D;11 @A9B=1 1;1 49291B;1=545;1C971A9B?A=1 $5=D491;5C9;13181H1=59771;1 @A9B=1=5D:D D41A1 3181H1 C5AB52DC 1;1 49291B;1 =5:1D89 71A9B ?A=1 ,5C518=55F1C9@A9B=13181H1=5711=945E91B9 5B1AH1BD4DC45E91B9 H17 4911=9 3181H1 14118 B521719 25A9;DC )5A81C9;1 $0%$4 )5A81C9;1 . 6 41
  • 153. 6 .
  • 154. J 6 6 )5A81C9;1 J .1 J .2 Gambar 6.27 Prisma segitiga Gambar 6.28 Jalannya sinar pada prisma sinar bias )
  • 155. J 6 6
  • 156. J J J 6 6 . 6 6 Contoh 6.10 + . +
  • 160. . .
  • 161. B9
  • 163. .
  • 164. B9 '919 49C5CD;1B52171925A9;DC 2 1 1 i r r 2 i 60 19,47 40,53 $5=D491919. 49C5CD;1B52171925A9;DC
  • 165. +
  • 166. B9 B9 B9 B9 J . . . + B9 . . 1A3B9 .
  • 168. . 6 J
  • 169. JLJ
  • 170. J 124 Mudah dan Aktif Belajar Fisika untuk Kelas X 1 2 r i L
  • 172. J 6
  • 173. J 6
  • 174. J 6 6
  • 175. L.
  • 176. .
  • 177. . L.
  • 178. 1 2 i r L
  • 180. BD4DC 291B 41A9 B91A =1BD;
  • 181. BD4DC 41C17 B91A =1BD; . BD4DC 291B 41A9 B91A ;5D1A BD4DC 41C17 B91A ;5D1A BD4DC 45E91B9 ,52D18@A9B=1C5A2D1C41A9;131+
  • 183. J +
  • 185. =549D=D41A1 J ,D4DC45E91B94989CD74571=577D1;1@5AB1=11 1 2 i r (58;1A51
  • 188. ,5C91@ B91A H17 41C17 @141 @A9B=1 1;1 =5711=9 45E91B9 H17 =5781B9;1 BD4DC 45E91B9 C5AC5CD ,118 B1CD B91A 41C17 C5AC5CD @1BC91;1=5781B9;1919BD4DC45E91B9=99=D= $1@1;?49B9;8DBDB P S T Q r1 ri 2 2 i1 R B
  • 189. Cahaya dan Optika 125 77 A3?8/27 3?2/@/?9/ 6/@7: 3;0B9A7/ # 2//A A3?8/27 /2/ @//A @B2BA 2/A/5 3?A/;/ @/;/ 235/ @B2BA 07/@ 932B/
  • 192. K 7:/7
  • 193. 27;/@B99/ 93 2/:/; %12!-!!.
  • 194. 7 @36755/ 23C7/@7 ?7@;/ ;38/27
  • 195. K K K
  • 196. 3?2/@/?9/ B9B; *3::7B@
  • 197. @7 @7 K
  • 202. @7
  • 203. @7
  • 204. @7 @7
  • 205. @36755/ 79/ 9317: @7
  • 208. K
  • 211. K
  • 212. K K
  • 214. #3A3?/5/ @B2BA 23C7/@7 ;77;B; 1,2 n @B2BA07/@?3:/A74;327B;
  • 215. A3?6/2/;327B; @B2BA 23C7/@7 ?7@;/ Contoh 6.11 *30B/6?7@;/E/5A3?0B/A2/?79/1/E/5;3;7:797@B2BA3;07/@ I 27:3A/99/2/:/;;327B;/7?79/@303?9/@@7/?2/A/52/?7/7? ;3;/@B97 ?7@;/03?//9/6@B2BA23C7/@7;77;B;?7@;/A3?@30BA !5! 793A/6B7 I ;327B;/7?
  • 218. 8. Lensa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
  • 219. 2/B:3@/139B59=9/4/A/B:3@/ 27C3?53 /2/:/6 :3@/ E/5 0/57/ A35/6E/ :3076 A77@ 2/?7/2/ 0/57/ A37E/ $3@/ 77 03?@74/A ;3E30/?9/ 03?9/@ @7/? !-!1
  • 220. *303:B;:30768/B6;3;/6/;743=;3/43=;3/E/5A3?8/27/2/ :3@/ 2/ 6/?B@ ;353A/6B7 0/57/0/57/ :3@/ 235/ 0/79 (/2/ :3@/ A3?2//A B@/A =A79 A7A79 4=9B@ 2/ B@/A 93:359B5/ :3@/ !-!1
  • 221. ;3;3?:76/A9/@93;/@30B/6:3@/2/0/57/0/57/E/ a. Pembiasan Cahaya pada Lensa Cembung /6/E/E/58/AB6/2/3?;B9//:3@/13;0B5/9/;35/:/;7 3;07/@/ 3?9/@03?9/@ @7/? 2/A/5 /9/ 2707/@9/ @36755/ 03?9/@ 03?9/@ @7/? 07/@E/ ;35B;B: (3?6/A79/ !-!1
  • 222. /57/ :3@/ E/5 A30/: /9/ ;356/;0/A 1/6/E/ :3076 0/E/9 2/?7 /2/ 0/57/ :3@/ E/5 A77@ ':36 9/?3/ 13/A ?/;0/A 1/6/E/ 27 2/:/; :3@/:30769317:2/?7/2/27B2/?/03?9/@03?9/@@7/?07/@/9/;35B;B: !AB:/6 @30/0E/ :3@/ 13;0B5 03?@74/A 9=C3?53 ).!12).!1 )23)-%5! 0!$! ,%.2! #%-4.' /E/5/ 032/ =:36 :3@/ 13;0B5 2//A 2703AB9 235/ 1/?/ ;355/;0/?9/ @7/?@7/? 7@A7;3D/E/ *7/?@7/? 7@A7;3D/ /2/ :3@/ 13;0B5 /2/ A75/ 0B/6 E/7AB @30/5/7 03?79BA / *7/?E/52/A/5@38/8/?@B;0BBA/;/2707/@9/;3:/:B7A7A794=9B@ /9A74 :3@/ 0 *7/? E/5 2/A/5 E/5 ;3:/:B7 A7A79 4=9B@ /@74
  • 223. 2707/@9/ @38/8/? @B;0B BA/;/ 1 *7/? E/5 2/A/5 ;3:/:B7 B@/A =A79 A72/9 ;35/:/;7 3;07/@/ Gambar 6.30 Lensa cembung bersifat konvergen (mengumpulkan cahaya) Gambar 6.31 Lensa cekung bersifat divergen (menyebarkan cahaya) Gambar 6.32 Bagian-bagian lensa cembung dan lensa cekung F1 F2 F1 F1 126 Mudah dan Aktif Belajar Fisika untuk Kelas X K K
  • 224. I = K II Keterangan: O = pusat optik OF1 = jarak fokus dari pusat optik OP1= jari-jari kelengkungan lensa F1 dan F2 = titik fokus P1 dan P2 = pusat kelengkungan lensa Gambar 6.33 Sinar-sinar istimewa pada lensa cembung F2 F2 (a) (b) (c) F P F1 O F2 P2 2 F1 P P 1 O
  • 225. F2 F1 A Gambar 6.35 Pembentukan bayangan oleh lensa cembung F1 F2 F1 F2 0 0 F0 F1 2 Cahaya dan Optika 127 B O ruang benda I I I ruang benda I I ruang benda I ruang benda IV ruang bayangan (IV ) ruang bayangan (I) ruang bayangan (III) ruang bayangan (II) Gambar 6.34 Penamaan ruang pada lensa cembung !.'+!( 0%-%.34+!. !6!.'!. 0!$! ,%.2! #%-4.' ,AB9;3;3?;B2/63;03AB9/0/E/5/?B/52723/2/27 03:/9/5 :3@/ 270/57 ;38/27 0303?// ?B/5/ @33?A7 /2/ !-!1
  • 226. 03?79BA #3A3?/5/ ! !! !!! 2/ !- /2/:/6 =;=? ?B/5 032/ ! !! !!! 2/ !- /2/:/6 =;=? ?B/5 0/E/5/ *3A7/:3@/;3;7:7972B/0B/6A7A794=9B@27@303:/697?72/9//E/ /?/9 932B/ 4=9B@ A3?@30BA @/;/ (3?6/A79/ !-!1
  • 227. BAB9 ;355/;0/?9/ 0/E/5/ 032/ E/5 276/@7:9/ =:36 :3@/ 13;0B5 27:/9B9/ 1/?/ @30/5/7 03?79BA / 7:B97@ 2B/ 0B/6 @7/? 7@A7;3D/ /2/ :3@/ 13;0B5 0 *7/?@3:/:B2/A/52/?73?;B9//:3@/2/2707/@9/9303:/9/5:3@/ 1 (3?=A=5/ /A/?/ 2B/ @7/? 07/@ ;3?B/9/ :3A/9 0/E/5/ 79/ 3?=A=5/272//A2/?7 3?/8/5/@7/? 07/@ 0/E/5/03?@74/A ;/E/ 2/ 27:B97@9/ 235/ 5/?7@ BAB@BAB@ b. Pembiasan Cahaya pada Lensa Cekung 3?032/ 235/ :3@/ 13;0B5 :3@/ 139B5 03?@74/A ;3E30/?9/ 03?9/@@7/?3?9/@@7/?E/58/AB6/2/3?;B9//:3@/139B5/9/ 2707/@9/ @31/?/ ;3E30/? ).!12).!1)23)-%5!0!$!,%.2!#%+4.' (/2/ :3@/ 139B5 8B5/ A3?2//A @7/?@7/? 7@A7;3D/ E/5 03?5B/ 0/57 3;03AB9/ 0/E/5/ *7/?@7/? 7@A7;3D/ /2/ :3@/ 139B5 /2/:/6 @30/5/7 03?79BA !-!1
  • 228. / *7/? E/5 2/A/5 @38/8/? @B;0B BA/;/ 2707/@9/ @3/9//9/ 03?/@/: 2/?7 A7A79 4=9B@ 0 *7/?E/52/A/5;3B8BA7A794=9B@
  • 229. 2707/@9/@38/8/?@B;0BBA/;/ 1 *7/? E/5 2/A/5 ;3:/:B7 B@/A =A79 27A3?B@9/ A72/9 ;35/:/;7 3;07/@/ !.'+!(0%-%.34+!.!6!.'!.0!$!,%.2!#%+4.' (3?6/A79/ !-!1
  • 230. ,AB9 ;355/;0/?9/ 0/E/5/ 032/ E/5 276/@7:9/ =:36 :3@/ 139B5 27:/9B9/ 1/?/ @30/5/7 03?79BA / 7:B97@ 2B/ 0B/6 @7/? 7@A7;3D/ :3@/ 139B5 0 *7/?@3:/:B2/A/52/?73?;B9//:3@/2/2707/@9/9303:/9/5:3@/ 1 32/ E/5 27:3A/99/ 27 23/ :3@/ 139B5 @3:/:B ;356/@7:/ 0/E/5/ E/5 ;3;7:797 @74/A ;/E/ A35/9 273?9317: 2/ A3?:3A/9 27 23/ :3@/ 139B5 (a) (b) (c) Gambar 6.36 Sinar-sinar istimewa pada lensa cekung Gambar 6.37 Pembentukan bayangan oleh lensa cekung F2 B B’ A’ F1 A O s’ f s h h’
  • 233. K R1 R2 R1 R2 (d) (e) (f ) Ingatlah Konvensi tanda untuk pembentukan bayangan oleh lensa: J s bernilai + (Objek nyata) untuk benda-benda di depan permukaan (sisi datang); bernilai – (Objek maya)untuk benda-benda di belakang permukaan (sisi transmisi); J s’ bernilai + (Bayangan nyata) untuk bayangan-bayangan di depan permukaan (sisi transmisi); bernilai – (Bayangan maya) untuk bayangan-bayangan di depan permukaan (sisi datang); J r, f bernilai + jika pusat kelengkungan berada pada sisi transmisi; bernilai – jika pusat kelengkungan berada pada sisi datang. Tugas Anda 6.1 Contoh 6.13 128 Mudah dan Aktif Belajar Fisika untuk Kelas X K
  • 234. K
  • 244. K
  • 245. K
  • 248. 1; Gambar 6.38 Lensa tipis (a) bikonveks, R1 0 ; R2 0 (b) konvek konkaf, R1 0 ; R2 0 (c) plan konveks, R1 = ; R2 0 (d) bikonkaf, R1 0 ; R2 0 (e) konkaf konveks, R1 0 ; R2 0 (f ) plan konkaf, R1 = ; R2 0 %.2! 3)0)2 $3@/ A77@ /2/:/6 :3@/ E/5 ;3;7:797 93A30/:/ 8/B6 :3076 9317: 270/2759/ 235/ 27/;3A3? 93:359B5/E/ $3@/ A77@ 2//A 27:/;0/59/ 235/ @30B/6 5/?7@ (/2/ !-!1
  • 249. 27AB8B99/ 0303?// 837@ :3@/ A77@ /:/; :3@/ A77@ 03?:/9B 3?@/;// 03?79BA
  • 251. (a) (b) (c) R1 R1 R2 R2 R1 R2 R1 R2 c. Perbesaran Bayangan Lensa (353?A7/ 3?03@/?/ 0/E/5/ /2/ :3@/ @/;/ 235/ 353?A7/ 3?03@/?/ 0/E/5/ /2/ 13?;7 :359B5 (3?03@/?/ 0/E/5/ 2723 477@79/ @30/5/7 3?0/275/ /A/?/ A7557 0/E/5/ 2/ A7557 032/ /A/B 8/?/9 0/E/5/ A3?6/2/ :3@/ 2/ 8/?/9 032/ 93 :3@/ *31/?/ ;/A3;/A7@ 2//A 27AB:7@ /A/B ' K
  • 252. #3A3?/5/ 3?03@/?/ 0/E/5/ 8/?/90/E/5/93:3@/ A7557 0/E/5/ 8/?/9032/93:3@/ A7557 032/ 79/ =@7A74 03?/?A7 0/E/5/ 03?@74/A ;/E/ 2/ A35/9 79/ K 35/A74 03?/?A7 0/E/5/ 03?@74/A E/A/ 2/ A3?0/:79 *30B/6032/03?27?7A35/9 1;2723/:3@/A77@9=C3?53E/58/?/94=9B@E/ 1;+3AB9/ / :3A/90/E/5/ 0 3?03@/?/0/E/5/ 1 @74/A0/E/5/ Perhatikan kembali gambar pembentukan pada lensa cembung dan lensa cekung. Temukan oleh Anda sehingga diperoleh Persamaan (6–24).
  • 253. lensa Fresnel Cahaya dan Optika 129 !5! 793A/6B7 1;2723/:3@/ 1;:3@/9=C3?53/A/B13;0B5 / $3A/90/E/5/ K
  • 254. K /270/E/5/032/03?/2/ 1;2703:/9/5:3@/ 0 (3?03@/?/ K K 1; % 1; K A/2/35/A74;3B8B99/0/E/5/E/A/2/A3?0/:79 /273?03@/?/0/E/5/E/ 1 *74/A0/E/5/ J E/A/2/A3?0/:7903?2/@/?9/7:/7K35/A74 J @/;/03@/?235/032/E/03?2/@/?9/7:/7 Informasi Sebuah lensa Fresnel adalah lensa plan-konveks yang tebal dibentuk berlipat-lipat agar diperoleh lensa datar yang memiliki sifat optiknya, namun lebih tipis sehingga memiliki kehilangan penyerapan yang lebih sedikit. Lensa Fresnel biasanya tipis dan lentur, ukurannya sekitar 0,015 inch (0,38 mm) dengan alur lekukan pada satu permukaan. Salah satu penerapan lensa Fresnel adalah untuk alat pemfokusan sensor inframerah. Lensa Fresnel dapat memperpanjang rentang pendeteksian mencapai 100 kaki. A Fresnel lens is a plano convex lens that has been collapsed on it self to form a flat lens that retains its optical characteristics but is much thinner and therefore has less absorption loss. A Fresnel lens is ussually thin and flexible and is about 0,015 inch (0,38 mm) thick with grooves molded on one surface. One of an application of Fresnel lens is to focusing devices for infrared sensors. A Fresnel lens can extend detection range to about 100 feet. Sumber: www.glolab.com inframerah untuk Anda Information for You d. Kekuatan Lensa /?/9 4=9B@ @30B/6 :3@/ @/5/A 3A75 /?A7E/ 9/?3/ 2//A ;3E/A/9/ B9B?/ 939B/A/ :3@/ #39B/A/ @30B/6 :3@/ @/5/A 03? 5/AB5 /2/ 7:/7 8/?/9 4=9B@ :3@/ A3?@30BA #39B/A/ :3@/ @7;0=: 2723477@79/ @30/5/7 93;/;B/ ;35B;B:9/ /A/B ;3;/1/?9/ 03?9/@1/6/E/3@/?E/939B/A/:3@/03?0/275A3?0/:79235/8/?/9 4=9B@E/ 79/ 8/?/9 4=9B@E/ 03@/? 939B/A/ :3@/ 9317: *30/:79E/ 879/ 8/?/9 4=9B@ :3@/ 9317: 939B/A/ :3@/ 03@/? *31/?/ ;/A3;/A7@ 3?E/A// A3?@30BA 27AB:7@ K
  • 255. #3A3?/5/ 939B/A/ :3@/ 27=A?7 8/?/94=9B@;3A3? */AB/ 2/:/; 27=A?7 879/ 8/?/9 4=9B@ :3@/ 27E/A/9/ 2/:/; ;3A3? ,AB9 :3@/ 13;0B5 7:/7 ( @3:/:B 03?7:/7 =@7A74 9/?3/ 7:/7 =@7A74 *30/:79E/ BAB9 :3@/ 139B5 7:/7 35/A74 K 9/?3/ 7:/7 8/?/9 4=9B@ :3@/ 139B5 35/A74 K Contoh 6.14 *30B/6:3@/9=C3?53;3;7:7978/?/94=9B@1;3?//9/6939B/A/:3@/ A3?@30BA !5! 793A/6B7 1;:3@/9=C3?53/A/B13;0B5 3?2/@/?9/3?@/;// ;3A3? 27=A?7 /27939B/A/:3@/27=A?7
  • 256. e. Susunan Dua Lensa :/A/:/A=A79@33?A7;79?=@9=2/A3?==5;355B/9/2B/0B/6 :3@//A/B:3076/E/5//967?E/5A3?03AB9;3?B/9/6/@7:2/?7?=@3@ 3;07/@/=:36932B/:3@/A3?@30BA%B:/;B:/1/6/E/2/?7032/1/6/E/ /AB:/ 2707/@9/ =:36 :3@/ 3?A/;/ @36755/ A3?03AB9 0/E/5/ ! /E/5/ ! 77 93;B27/ @3=:/6=:/6 ;3?B/9/ 032/ 0/57 :3@/ 932B/ /E/5/ !! /A/B 0/E/5/ A3?/967? A3?03AB9 =:36 :3@/ 932B/ /?/ ;33AB9/ 0/E/5/ 0/79 235/ 1/?/ 5/;0/? ;/BB 1/?/ 3?67AB5/ A3A/ ;3579BA7 93A3AB/ E/5 A3:/6 270/6/@ @303:B;E/ bayangan pertama (I) F2 F1 F1 F2 bayangan akhir (II) lensa II (+) lensa I (+) benda sI s'I s'iII s'II L 3?2/@/?9/!-!1
  • 257. A3?@30BA2/9/?3//A/?932B/:3@/;3 ;7:797 8/?/9 A3?A3AB @7;0=: ;/9/ A3?2//A 6B0B5/ @30/5/7 03?79BA Gambar 6.39 Pembentukan bayangan oleh dua buah lensa cembung Tes Kompetensi Subbab C %1*!+!.,!($!,!-4+4,!3)(!. +=5/?@32/5;3:/9B9/39@3?7;3BAB9;33AB9/ 9313/A/ 1/6/E/ 27 2/:/; 0/6/ 9/1/ A30/: !/ ;3:3/@9/@303?9/@1/6/E//2/3?;B9//9/1/A30/: 235/@B2BA I+3?E/A/03?03:=9272/:/;9/1/ 235/03@/?3;03:=9/A3?6/2/5/?7@=?;/:
  • 258. I79/ 9313/A/1/6/E/27B2/?/ ; @03?//9/613/A ?/;0/A1/6/E/272/:/;9/1/A30/:A3?@30BA 79/7239@07/@;BA:/9/7? 2/7239@07/@;BA:/9 /:9=6=: A3AB9/ / 7239@07/@/7??3:/A74A3?6/2//:9=6=: 0 7239@07/@/:9=6=:?3:/A74A3?6/2//7? 2/9/66B0B5//A/?/7:/77239@07/@2/93?//A/ ;/@@/@B/AB032/ 130 Mudah dan Aktif Belajar Fisika untuk Kelas X *30B/6032/03?27?7A35/92723/:3@/139B5E/5 ;3;7:7978/?/94=9B@ 1;$B97@:/60/E/5/032/ E/52703AB9=:3613?;7139B5A3?@30BA879/ / 032/A3?:3A/91;2723/:3@/139B5 0 032/A3?:3A/9
  • 259. 1;2723/:3@/139B5 1 032/A3?:3A/9 1;2723/:3@/139B5 B/0B/6:3@/13;0B527@B@B@323;797/?B/ @36755/@B;0BBA/;/03?7;7A$3@/3?A/;/;3 ;7:7978/?/94=9B@
  • 260. 1;2/8/?/94=9B@:3@/932B/ 1;*30B/6032/E/5A7557E/1;03?27?7A35/9 2723/:3@/3?A/;//2/8/?/9 1;+3AB9/ / 5/;0/?3;03AB9/0/E/5//967? 0 :3A/90/E/5//967? 1 A75570/E/5//967?2/@74/A0/E/5//967? 2 3?03@/?/A=A/: Kata Kunci • pembiasan (refraksi) • indeks bias • sudut datang • sudut bias • sudut kritis • kaca plan paralel • prisma • deviasi minimum • lensa sferis ! !! #3A3?/5/ 8/?/9 /A/?:3@/ ! 8/?/9 0/E/5/ :3@/ ! !! 8/?/9 032/ :3@/ !! K
  • 261. D. Alat-Alat Optik (353A/6B/ ;/B@7/ ;353/7 =A79 A3:/6 ;3:/67?9/ 723723 270B/AE/ /:/A/:/A =A79 :/A/:/A =A79 27@30BA 8B5/ @30/5/7 3?/:/A/ E/5;3;/4//A9/@74/A@74/A0/6/93A79/2793/71/6/E//6/0/6/ 77 ;38/27 7@A7;3D/ 9/?3/ 03AB9E/
  • 262. sklera otot siliar iris lensa pupil kornea cairan di sekitar mata Gambar 6.40 Bagian-bagian mata retina fovea pangkal saraf optik lensa lebih cembung bayangan difokuskan pada retina (a) benda dekat lensa lebih pipih (b) benda jauh Gambar 6.41 Gambaran daya akomodasi mata Cahaya dan Optika 131 1. Mata (3?/69/2/;3;0/E/59/0/5/7;//879/;/B@7/A72/927:35 9/7235/;/A//E/52/?/@/9/93A79/2/;3;38/;9/;/A/ BAB9 0303?// @//A #372/6/ 2/ 67?B979B9 93672B/ ?/@/E/ A72/9 0357AB03?/?A7/2/79/A/+B6/./5%/6/9B/@/A72/9;35/?B7/9/;/A/ 93/2/ 2/ /5/7;// ?7@7 93?8/ ;/A/ 93A79/ ;3:76/A @30B/6 =0839 (3?6/A79/:/60/5/;/A//2/!-!1
  • 263. (/2/D/9AB;/A/;3:76/A =0839 :3@/ ;/A/ /A/B :3@/ 9?7@A/:7 ;3;03AB9 0/E/5/ 032/ /2/ ?3A7/ E/5 03?/2/ 27 0/57/ 03:/9/5 ;/A/ )3A7/ 77 276B0B59/ =:36 @/?/4@/?/4 35:76/A/ 93 =A/9 @36755/ A7;0B: 93@/ ;3:76/A 032/ /A/B =0839$3@/;/A/;3?B/9/:3@/E/5A30/:A77@E/2//A03?B0/6@3@B/7 235/:3A/9032/E/5@32/5;38/27=083935:76/A/(3?B0/6/A30/: A77@E/ :3@/ ;/A/ 77 ;35B0/6 8/?/9 4=9B@ :3@/ ;/A/ 35/ 1/?/ 77 :3A/90/E/5/032/E/5@32/5;38/273?6/A7//9/@3:/:B8/AB6A3/A 27 ?3A7/ @36755/ 0/E/5/ E/A/ 2/?7 032/ 2//A 27A3?7;/ 235/ 83:/@ 879/ 0/E/5/ A3?@30BA A3/A 8/AB6 27 ?3A7/ /?/9?3A7/235/:3@//2/:/6A3A/*3;3A/?/7AB@3A7/032/E/5 ;38/273?6/A7/;3;7:7978/?/9E/5A72/9@/;/A3?6/2/:3@/;/A/2/ 032/E/5239/A@32/52/8/B60/69/8/B6@39/:732/032/A3?@30BA 2//A A3?:76/A 879/ 0/E/5/ 032/E/ A3/A 8/AB6 27 ?3A7/ ':36 9/?3/ 7AB @/AB@/ABE/ 1/?/ E/5 ;B597 /2/:/6 235/ 3?B0/6/ 8/?/9 4=9B@ :3@/ ;/A/ /27 3?B0/6/ :3@/ ;/A/ @3@B55B6E/ BAB9 ;32//A9/ 0/E/5/ E/A/ 27 ?3A7/ a. Daya Akomodasi #3;/;B/ :3@/ ;/A/ BAB9 ;35B0/6 8/?/9 4=9B@E/ 27@30BA (/2/@//A;/A/;3:76/A032/E/5239/A=A=A=A=A@7:7/?;335/5 @36755/ :3@/ ;/A/ :3076 13;0B5 *30/:79E/ /2/ @//A ;3:76/A 032/ E/58/B6=A=A=A=A@7:7/?;3532B??7:39@@36755/:3@/;/A/:3076776 (/2/ 93/2// =?;/: =A=A=A=A @7:7/? 03?/2/ 2/:/; 93/2// ?7:39@ /;B @327 3579/A 2/:/; 93/2// A35/5 (/2/ 93/2// 77 03AB9 :3@/ ;/A/ /5/9 2/A/? (/2/ 93/2// 77 ;/A/ 2/:/; 93/2// A72/9 03? /9=;=2/@7 79/032/E/58/B6A/96755/27239/A9/=A=A=A=A@7:7/?/9/;3 8/27 A35/5 'A=A @7:7/? /9/ 03?A/;0/6 A35/5 879/ 032/ @3;/97 239/A (/2/ 93/2// 77 ;/A/ 2/:/; 93/2// @32/5 03?/9=;=2/@7 79/ ;/A/ A3?B@ 03?/9=;=2/@7 ;/A/ A3?/@/ :3:/6 9/?3/ =A=A @7:7/? A3?B@ ;335/5 b. Titik Dekat dan Titik Jauh 32/ 6/E/ 2//A A3?:76/A 235/ 83:/@ 879/ A3?:3A/9 27 2/3?/6 35:76/A/ ;/A/ /3?/6 35:76/A/ ;/A/ 77 03?/2/ 27 /A/?/ A7A79 239/A ;/A/ /A/B ! % 2/ A7A79 8/B6 /A/B ! ! 79/ 032/ 03?/2/ 27 :B/? 2/3?/6 35:76/A/ A3?@30BA ;/A/ A72/9 /9/ ;3:76/A 032/ A3?@30BA 235/ 83:/@ +7A79239/A/2/:/6A7A79A3?239/AE/52//A27:76/A;/A/@31/?/83:/@ 235/;/A/03?/9=;=2/@7;/9@7;B;@32/59/A7A798/B6/2/:/6A7A79 A3?8/B6 E/5 2//A 27:76/A ;/A/ @31/?/ 83:/@ 235/ ;/A/ A72/9 03?/9=;=2/@7(/2/;/A/=?;/:A7A79A3?8/B6/2/:/627A7A79A/96755/ (3?6/A79/ !-!1
  • 264. 03?79BA Gambar 6.42 Daerah penglihatan PR = ~ PP = 25 cm jangkauan penglihatan
  • 265. Contoh 6.15 79/:3@/;/A/27/55/@43?7@0=:/235/8/?/93?;B9//23/:3@/235/ ?3A7/ 1;67AB5:/6 / 9B/A:3@/;/A/=?;/:93A79/;/A/;3:76/A032/E/58/B6@39/:7;/A/A72/9 03?/9=;=2/@72/93A79/;3:76/A032//2/8/?/9
  • 266. 1;;/A/03?/9=;=2/@7 ;/9@7;B; 0 3?B0/6/939B/A/:3@/;/A/2/?7A72/903?/9=;=2/@7@/;/703?/9=;=2/@7 ;/9@7;B; !5! 793A/6B7 1; / (/2/@//A;/A/A72/903?/9=;=2/@7 27=A?7 27=A?7 /279B/A;/A/=?;/:/2/@//AA72/903?/9=;=2/@7/2/:/6 27=A?72/ /2/@//A;/A/03?/9=;=2/@7/2/:/6 27=A?7 c. Cacat Mata dan Penanggulangannya (/2/93E/A//E/;/A/;/B@7/A72/9@3;B/E/=?;/:#3A72/9 =?;/:/ ;/A/ ;/B@7/ @3?75 27@30BA 1/1/A ;/A/ /A/B /03?/@7 (/2/ B;B;E/;/@/:/61/1/A;/A/A3?8/279/?3/0/E/5/032/A72/9A3/A 8/AB627?3A7/2/E/5;35/:/;71/1/A;/A/9/?3/0/E/5/032/ 8/AB6 27 23/ ?3A7/ 2/ /2/ B:/ E/5 8/AB6 27 03:/9/5 ?3A7/ /1/A ;/A/2//A27A/55B:/57235/;355B/9/9/1/;/A/:3@/9=A/9 /A/B =3?/@7 ;/A/ %/A/=?;/:/A/B3;3A?=7/2/:/6;/A/E/5;3;7:79793;/;B/ ;3:76/A 032/ /2/ 2/3?/6 35:76/A/ =?;/: E/7AB /A/?/ A7A79 239/A
  • 267. 1; 2/ A7A79 8/B6 A/9 6755/ 3?79BA 77 0303?// 837@ 1/1/A ;/A/ E/5 @3?75 27/:/;7 =:36 ;/B@7/ )/0) !4. !4( %/A/E/5;35/:/;71/1/A;7=7E/7AB;/A/E/5;3;7:797A7A79239/A @/;/235/
  • 268. 1;
  • 269. 1;2/;3;7:797A7A798/B6A3?A3AB (323?7A/1/1/A;/A/77A72/92//A;3:76/A032/E/58/B6@30/0:3@/ ;/A/;7=7;313;0B52/A72/92//A;38/27776@30/5/7;//;/A/ =?;/: 970/AE/ 0/E/5/ 032/ 8/B6 @3:/:B 8/AB6 27 23/ ?3A7/ ,AB9;3/55B:/571/1/A;/A/;7=76/?B@27B/E/9//5/?0/E/5/ A3/A 8/AB6 27 ?3A7/ 3?/?A7 @303:B; @7/? 2/A/5 8/AB6 /2/ :3@/ ;/A/ A3?:3076 2/6B:B @7/? 2/A/5 77 6/?B@ 27@30/?9/ ':36 9/?3/ 7AB 6/?B@ 270/AB =:36 :3@/ 139B5 :3@/ 27C3?53 E/5 939B/A/ :3@/E/ @323;797/ ?B/ @36755/ ;/;B ;3;03AB9 0/E/5/ 032/ A3/A 8/AB6 sinar-sinar sejajar dari benda jauh lensa cekung 132 Mudah dan Aktif Belajar Fisika untuk Kelas X 1; ; (/2/@//A;/A/03?/9=;=2/@7
  • 270. 1;
  • 271. 1;
  • 272. ;
  • 273. 0 (3?B0/6/939B/A/:3@/ K K27=A?7 /273?B0/6/939B/A/:3@/K 27=A?7 Gambar 6.43 (a) Pada cacat mata miopi, bayangan benda selalu jatuh di depan retina. (b) Cacat mata miopi diatasi dengan menggunakan lensa cekung. (a) (b)
  • 274. (a) Ingatlah benda dekat (b) lensa cembung retina Cahaya dan Optika 133 27 ?3A7/ 5/? 2//A ;3:76/A 032/032/ 8/B6 323?7A/ ?/0B 8/B66/?B@;355B/9/:3@/9/1/;/A/E/5;356/@7:9/0/E/5/;/E/ 27 23/ :3@/ /2/ 8/?/9 E/5 @/;/ 235/ A7A79 8/B6E/ /27 BAB9 323?7A/ ?/0B 8/B6 /A/B ;7=7 03?:/9B 2/ K K
  • 275. Contoh 6.16 K 1; )0%1-%31/0) !4. %+!3 %/A/E/5;35/:/;71/1/A673?;3A?=7E/7AB;/A/E/5;3;7:797 A7A79239/A:307603@/?2/?7/2/
  • 276. 1;2/;3;7:797A7A798/B6A/96755/ (323?7A/ 1/1/A ;/A/ 77 A72/9 2//A ;3:76/A 032/ E/5 239/A A3A/7 2//A;3:76/A83:/@032/032/8/B6A//03?/9=;=2/@7/1/A77A3?8/27 9/?3/ /2/:/6 ;/A/ A72/9 2//A ;38/27 13;0B5 @30/5/7;// ;/A/ =?;/:970/AE/0/E/5/032/239/A@3:/:B8/AB62703:/9/5?3A7/ ,AB9 ;3/55B:/57 1/1/A ;/A/ 673?;3A?=7 6/?B@ 27B/E/9/ /5/? 0/E/5/ A3/A 8/AB6 27 ?3A7/ 3?/?A7 @303:B; @7/? 2/A/5 8/AB6 /2/:3@/;/A/A3?:30762/6B:B@7/?2/A/5776/?B@;35B;B:':36 9/?3/ 7AB 323?7A/ 6/?B@ 270/AB 235/ :3@/ 13;0B5 :3@/ 9=C3?53E/5939B/A/:3@/E/;/;B;3;03AB90/E/5/032/ @36755/ A3/A 8/AB6 27 ?3A7/ (3?6/A79/ !-!1
  • 277. 5/?323?7A/2//A;3:76/A032/032/239/A/2/8/?/9A3?A3AB 323?7A/ ?/0B 239/A 6/?B@ ;355B/9/ :3@/ 9/1/;/A/ E/5 ;356/@7:9/0/E/5/;/E/2723/:3@//2/8/?/9E/5@/;/235/ A7A79 239/AE/ K /27 BAB9 323?7A/ 673?;3A?=7 03?:/9B K K
  • 278. Gambar 6.44 (a) Pada cacat mata hipermetropi, bayangan benda selalu jatuh di belakang retina. (b) Cacat mata hipermetropi diatasi dengan menggunakan lensa cembung. Contoh 6.17 *3@3=?/5E/5;323?7A/673?;3A?=7;3;7:797A7A79239/A 1;5/?2//A;3:76/A 032/032/E/5239/A@33?A7;/A/=?;/:03?//9/68/?/94=9B@2/9B/A:3@/ E/56/?B@7/5B/9/ !5! 793A/6B7 K 1;A7A79239/A323?7A/673?;3A?=7
  • 279. K 1; ; Tanda negatif menunjukkan bahwa penderita miopi harus dibantu dengan lensa negatif atau lensa cekung (lensa divergen). *3@3=?/5E/5;323?7A/;7=7;3;7:797A7A798/B6 1;5/?7/2//A;3:76/A 032/032/E/58/B603?//9/68/?/94=9B@2/9B/A:3@/E/56/?B@275B/9/ 323?7A/;7=7A3?@30BA !5! 793A/6B7 K 1;A7A798/B6323?7A/;7=7 K 1;K; K
  • 280. /A/B K 27=A?7 K 1; /278/?/94=9B@:3@/K;2/939B/A/E//2/:/6 1 4 27=A?7
  • 281. 1 1
  • 282. 27=A?7 f 0,5 /278/?/94=9B@:3@//2/:/6 ;2/939B/A/03@/?E//2/:/6
  • 283. 27=A?7 1%2)/0) !3! 4! %/A/ AB/ ;3;7:797 =A=A @7:7/? E/5 A72/9 :/57 0/79 @33?A7 /2/ ;/A/ =?;/: 970/AE/ 93;/;B/ =A=A BAB9 03?/9=;=2/@7 /A/B ;35B0/6 8/?/9 4=9B@ :3@/ ;/A/ A72/9 @30/79 @33?A7 /2/ ;/A/ =?;/: (323?7A/ 1/1/A?3@07=7;3;7:797A7A79239/A:307603@/?2/?7/2/
  • 284. 1;2/A7A798/B6 /2/ 8/?/9 A3?A3AB @36755/ 323?7A/ ?3@07=7 A72/9 2//A ;3:76/A /A/B ;3;0/1//2/8/?/9=?;/:2/A72/92//A;3:76/A032/8/B6235/83:/@ /1/A;/A/?3@07=72//A27A/55B:/57;355B/9/:3@/?/59/ @33?A7 /2/ !-!1
  • 285. #/1/;/A/ 77 A3?27?7 /A/@ :3@/ 13;0B52/139B5,AB9;3:76/A032/8/B6323?7A/?3@07=72//A ;355B/9/:3@/139B52/BBAB9;3:76/A032//2/8/?/9=? ;/: 323?7A/ ?3@07=7 2//A ;355B/9/ :3@/ 13;0B5 Contoh 6.18 *3@3=?/59/939323?7A/?3@07=7;3;7:797A7A79239/A1;2/A7A798/B6 1;5/? 7/2//A;3:76/A032/E/5239/A@33?A7;/A/=?;/:2/2//A;3:76/A032/8/B6 03?//9/68/?/94=9B@:3@/074=9/:2/9B/A:3@/9/1/;/A/E/56/?B@275B/9/9/939 A3?@30BA !5! #/1/;/A/074=9/:A3?@B@B/A/@2B/:3@/0/57//A/@:3@/35/A74139B5/5/?2//A ;3:76/A8/B62/0/57/0/D/6:3@/=@7A7413;0B5/5/?2//A;3;0/1/=?;/: J ,AB92//A;3:76/A8/B6 2/ K 1; Ingatlah 134 Mudah dan Aktif Belajar Fisika untuk Kelas X K K K 1;K ; K K 27=A?7 /27BAB92//A;3:76/A032/8/B6275B/9/9/1/;/A/235/8/?/94=9B@ ;2/939B/A/:3@/K 27=A?7 J ,AB92//A;3:76/A032/239/A
  • 286. 2/ K1;
  • 287. K 1; ;
  • 289. 27=A?7 Gambar 6.45 Kacamata bifokal. Lensa (–) untuk melihat jauh, lensa (+) untuk melihat dekat. 23)'-!3)2-! @A75;/A7@;/;3?B/9/1/1/A;/A/E/527/970/A9/03AB99=?3/ A72/90B2/?/1/A;/A//@A75;/A7@;/2//A27A/55B:/57235/:3@/ @7:72?7@ $3@/ 77 2//A ;35B;B:9/ /A/B ;3E30/?9/ @7/? /2/ @/AB /?/6 @/8/ A// ;3;35/?B67 /?/6 :/7 2. Lup (Kaca Pembesar) ,AB9 2//A ;3:76/A 032/032/ 9317: /5/? A/;/9 :3076 03@/? 2/?7/2/B9B?/@303/?E/275B/9/:B$B;3?B/9/:3@/13;0B5 Pada Contoh Soal 6.18, tanda positif menunjukkan bahwa penderita hipermetropi harus dibantu dengan lensa positif atau lensa cembung (lensa konvergen).
  • 290. F F (b) Cahaya dan Optika 135 /A/B :3@/ =@7A74 *30/5/7;// 2/ 93A/6B7 :3@/ 13;0B5 ;3;7:797 93;/;B/ ;3;03AB9 0/E/5/ ;/E/ E/5 273?03@/? 879/ 032/ A3?:3A/927/A/?/A7A794=9B@2/:3@/,AB9:B032/@3:/:B27:3A/99/ 2/:/; ?B/5 ! @36755/ 0/E/5/ /9/ A3?:3A/9 27 ?B/5 !- /E/5/ E/5A3?:3A/927?B/5!-03?@74/A;/E/2/A35/9@36755/8/?/90/E/5/ E/5 2703AB9 :B @3:/:B 35/A74 03?A/2/ 35/A74 (/2/ @//A ;355B/9/ :B 8/?/9 032/ 27B0/6B0/6 @323;797/ ?B/ @36755/ 272//A9/ 0/E/5/ E/5 /:75 83:/@ 0/57 ;/A/ =?;/: E/7AB /2/ 8/?/9 0/1/ E/5 07/@/E/
  • 293. ! 2/
  • 294. +// :B 032/ A3?:76/A 235/ @B2BA @303@/? 2/B 879/ ;355B/9/ :B 032/ A3?:76/A =:36 ;/A/ 235/ @B2BA @36755/ 3?03@/?/ /5B:3?E/ @303@/? 2/ /5B:3? ;/9/
  • 296. K 79/ ;/A/ 03?/9=;=2/@7 /2/ 8/?/9 % ;/E/ 273?=:36 3? @/;// K % % % % K
  • 299. 7 /9/ 273?=:36 /5B:3? % % % % % /5B:/? K % #3A3?/5/ /5B:3? 3?03@/?/ /5B:3? A7A79 239/A ;/A/ 8/?/94=9B@:B % 8/?/9 /A/?/ 0/E/5/ 2/ :B K
  • 300. 79/ @B2BA 2/ @/5/A9317: A/ 2/ A/ ;/9/ K ':36 9/?3/ %12!-!!.
  • 301. 7 ;38/27 Gambar 6.46 Lup digunakan juga untuk memperjelas tulisan yang sangat kecil. PP (a) p Gambar 6.47 (a) Sudut penglihatan mata ( ), ketika benda dilihat tidak menggunakan lup. (b) Sudut penglihatan mata ( ), ketika benda dilihat dengan menggunakan lup. p' s P s' = PP Contoh 6.19 *30B/6:B;3;7:7978/?/94=9B@ 1; 7AB5:/63?03@/?/:B879/;/A/;3:76/A 032/235/03?/9=;=2/@7/2/8/?/9
  • 302. 1;
  • 303. 1;
  • 304. 1; 1; 1;
  • 306. 3. Mikroskop %79?=@9= /2/:/6 @30B/6 /:/A =A79 E/5 275B/9/ ;3:76/A 032/ 032/ @/5/A 9317: 1=A=6E/ C7?B@ 2/ 0/9A3?7 %79?=@9= ;3;7:797 3?03@/?/ /5B:3? :3076 03@/? 2/?7/2/ :B %79?=@9= A3?27?7 /A/@ 2B/ :3@/ 13;0B5 $3@/ E/5 239/A 235/ lensa objektif benda ;/A/ 27@30BA :3@/ =9B:3? @32/59/ :3@/ E/5 239/A 235/ 032/ 27@30BA :3@/ =0839A74 (3?6/A79/ @93;/ @B@B/ :3@/ ;79?=@9= /2/ !-!1