Mudah dan Aktif Belajar Fisika untuk Kelas XII
180
36?529:D25:D6B2?82?=6946 =1.,-
M52?.627 45;6 37M 6BEEC2?6B626?88E?22?D6B:
7:C:2=2C:C6A6BD:D6B::?6D:82C :6=2C1?52D6=296A6=2;2B:2D6B:A2?2C36?5236B9E3E?82?
56?82?6?6B8::?6D:=6E=82C -6B:6:A2BD:C:6?I2D22?329G2 6?6B8:DD2=82C52=2CE2DEBE2?82?D6BDEDEA5:328:C642B26B2D26
C6D:2A=6E=I2?8D6B52A2D5:52=2BE2?82? :26?6B8:DD2=C:CD6 252=2952?32?I2?I2=6E=I2?836B25252=2BE2?82?252=29
6?6B8:B2D2B2D2I2?85::=::=69C6D:2A=6E=252=29
?6B8::?: D6B2?5E?852=236?DE6?6B8::?6D:C6D:2A=6E= 2?D6D2A:D:52
36B2BD:C6E2=6E=6:=::6?6B8:I2?8C22I2:DE :=2:D6BC63ED 92?I2=296BEA22??:=2:B2D2B2D2
26 6A6B=:92D2? C632B2? 646A2D2? I2?8 5::=:: =6E= 82C ,632B2? 6?6B8: 646A2D2? 2B6?2 6?6B8: :?6D: C6=2=E
36B9E3E?82?56?82?646A2D2? =1.,-376=:92D329G2EBF2 C632B2?:DEC6BEA256?82?92C:=I2?85:A6B=69A252:?D6?C:D2CCA6DBE
B25:2C:D6B2= 6B6236B2?882A2?2526:B:A2?2?D2B2C:72DA2?2C 36?5252?B25:2C:D6B2= 6?82?A6?562D2?I2?86B62=2E2?
=1.,-37 6A6B=69 A6BEEC2? 329G2 :?D6?C:D2C B25:2C: 36B32?5:?8D6B32=:56?82?A2?82D6A2DA2?;2?886=32?8
.?DE I2?8 36C2B :?D6?C:D2C 22? C62:? 64:= A23:=2 6?562D:D29:?882:?D6?C:D2C22?6?562D: ?= 2= :?: C6CE2:
56?82?92C:=6A:B:C 2?D6D2A:2A23:=2 6?562D:?=92=:?:C2?82D 6?I:A2?8 52B: 92C:= 6A:B:C I2?8 6?E?;E2? 329G2 :?D6?C:D2C
6?562D:?=6D:2 C62:?6?864:= 6?I:A2?82? A6BC222? +2I=6:8962?C I2?8 C2?82D ;2E9 :?:
5:?222?N6?42?2.=DB2:=6DO2B6?2 I2?864:=36B25252=2 G:=2I2986=32?8E=DB2F:=6D
26
6?E?;E2? 9E3E?82? :?D6?C:D2C 52? A2?;2?8 86=32?82?D2B2EBF2+2I=6:8962?C52?EBF20:6? -6B:.3
52A2D6?6B2?82?CA6DBEA252A2?;2?886=32?8I2?8A6?56 D6D2A:6?I:A2?86D:26?6B2?82?A2?;2?886=32?8I2?8A2?;2?8
,632=:?I2 D6B: =1.,-37 52A2D 6?6B2?82? CA6DBE A252 A2?;2?886=32?8I2?8A2?;2?8D6D2A:6?I:A2?86D:26?6B2?82?
A2?;2?886=32?8I2?8A6?56
4. Teori Planck
-6B: =2C: D6?D2?8 4292I2 C63282: 86=32?8 6=6DB28?6D: 52A2D6?;6=2C2?52B:2?22C2=B25:2C:2=BD6D2A:D:523:C256?82?
D6A2D6AB65:C:2?CA6DBE4292I2I2?85:A2?42B2?C63282:2?2 I2?8D6B22D:=69.3 -6B:.32AE6?;6=2C2?B25:2C:36?52
9:D2E?DEA2?;2?886=32?8I2?8A6?56D6D2A:8282=E?DEA2?;2?8 86=32?8 I2?8 A2?;2?8 ,632=:?I2 D6B: =1.,-37 36B92C:=
6?;6=2C2?B25:2C:36?529:D2E?DEA2?;2?886=32?8I2?8A2?;2?8 D6D2A:8282=E?DEA2?;2?886=32?8I2?8A6?56
9:B?I2A6?;6=2C2?I2?86E2C2?=29:B52B:C6B2?87:C:2G2? 6B2?130M 26?4326=2E2?A6?562D2?
=2:?56?82?6?82;E2?CE2DEBEEC6A:B:C52?D6B?I2D2C2?82D44 56?82?92C:=A6?822D2??I2
v n v
Gambar 7.5
Sebaran jumlah partikel yang memiliki kecepatan v.
Te o
ri R
a yle
ig h
- J ea
ns Te
or i W
ien Intensitas
Panjang gelombang Te
o ri P
la n
ck
Gambar 7.6
Perbandingan teori Wien, dan teori Rayleigh-Jeans dengan
teori Planck yang memenuhi
data percobaan.
Tugas Anda 7.1
Carilah dari buku-buku tentang formula yang digunakan Rayleigh-
Jeans untuk menjelaskan intensitas
radiasi benda hitam.
DIUNDUH DARI: WWW.BUKUPAKET.COM Sumber buku bse.kemdikbud.go.id
Radiasi Benda Hitam
181
130 6?42B: 52C2B D6B: E?DE BEEC 6A:B:C?I2 E2 3E=2? 6E5:2?:236B92C:=63E2D2CEC:I2?8C2?82D6?86;ED2?A252
C22D:DEI2:DED6?D2?886D2B2?=6E==6E=5:A6BE22?36?52 9:D2 1306?86E22?ACDE=2D?I2C63282:36B:ED
?6B8: B25:2C: I2?8 5:A2?42B2? =69 86D2B2? =6E==6E= C:=2DB36?526BEA22?A26DA26DE2?D26?6B8: 6C2B?I2
6?6B8:52=2C6D:2AA26D6BEA22?6=:A2D2?3:=2?82?3E=2DCE2DE 36C2B2?NOI2:DE
?
M 56?82? 252=29 3:=2?82? 2C=:
I2?8 5:C63ED 3:=2?82?
E2?DE52?252=297B6E6?C:86D2B2?=6E==6E=C652?8 2?6BEA22??CD2?D2=2?4I2?836C2B?I2
P
M
C =69 2B6?2 6?6B8: B25:2C: 36BC:72D 5:CB:D 5:2D22? 6?6B8:?I2
D6BE2?D:C2C:52?6?6B8:I2?85:A6B3=692?56?82? 5:C63EDD:?82D6?6B8:
=6E==6E=6?I6B2A2D2E62?42B2?6?6B8:B25:2C:4292I2 52=2A26D5:CB:DI2?85:C63EDE2?DE2D2E7D? ?6B8:7D?
2B6?2A6B36522?5E2D:?82D6?6B8:C6A6BD:D2A2A25226 252=29
M :2 =6E==6E= 6?I6B2A
62?42B2? 7D? D:?82D
6?6B8:?I236BD23292D2E36BEB2?8C636C2B 282C2?130:?: 36B=2EE?DE36?529:D2
2?82913056?82?ACDE=2D?I2329G26?6B8:C:=2DBD6BE2?D:C2C: 6BEA22?C63E29D6B3C2?36C2B130C6?5:B:36BC22:=EG2?
C62?82D2??I2D:526?I252B:92=:DE 282C2?=2?45:2?882AC63282: D?8822G2=7:C:2E2?DE
E n
1 2
3 4
ke n =
1hf 2hf
3hf 4hf
Gambar 7.7
Tingkat-tingkat energi yang diperkenankan untuk satu
molekul yang frekuensinya f.
E=29:?:E7D?4292I2I2?8A2?;2?886=32?8?I2 ?E?DE 6?:3E=2?B2?8C2?82?F:CE2=A2522D2?B2=252=297D?A6BC6?
:246A2DB232D4292I2P C52?P
M
CD6?DE2?=2952I2 4292I2D6BC63ED
; ?6B8:4292I236B52C2B2?6723?252=29
2I24292I2D6BC63ED52A2D5:D6?DE2?C63282:36B:ED
- - C
C
C
Contoh
7.5
Tantangan
untuk Anda
Perumusan Rayleigh-Jeans tidak cocok diterapkan untuk radiasi
benda hitam pada daerah panjang gelombang pendek. Dapatkah Anda
menduga
, apa implikasi dari
persamaan Rayleigh-Jeans pada daerah panjang gelombang pendek
untuk kehidupan di Bumi?
DIUNDUH DARI: WWW.BUKUPAKET.COM Sumber buku bse.kemdikbud.go.id
Mudah dan Aktif Belajar Fisika untuk Kelas XII
182
5. Aplikasi Radiasi Benda Hitam untuk Mengukur Suhu Matahari
