Bab 7 Radiasi Benda Hitam

menganalisis secara kualitatif gejala kuantum yang mencakup hakikat dan sifat-sifat radiasi benda hitam, serta penerapannya.

Setelah mempelajari bab ini, Anda harus mampu:

menganalisis berbagai besaran fisis dan gejala kuantum dan batas-batas berlakunya relativitas Einstein dalam paradigma Fisika Modern.

Hasil yang harus Anda capai:

Radiasi Benda Hitam

A. Pengertian Radiasi

Benda Hitam

B. Dualisme

Gelombang

Partikel

'2D292B:>6BEA2<2?CE>36B<69:5EA2?5:E>: ?6B8:I2?85:A2?42B<2? '2D292B:>6>32?DEC6>E2DE>3E92?36B<=@B@7:=E?DE<>6=2<E<2?7@D@C:?D6C:C I2:DEAB@C6CA6>3E2D2?>2<2?2? -E>3E92?>6BEA2<2?CE>36B>2<2?2? ED2>2328:>2?EC:252?96G2? $25:C642B2D:52<=2?8CE?8>2?EC:252?96G2? 36B82?DE?8A2526?6B8:I2?85:A2?42B<2?'2D292B: ,6=2:?:DE6?6B8:I2?8 5:A2?42B<2?'2D292B:>6>3E2DCE9E5:E>:D6D2A92?82DD:52<D6B=2=E5:?8:? C69:?882<69:5EA2?5:E>:D6D2AD6B;282 *6B?29<2??5236BA:<:B36B2A2 36C2B6?6B8:I2?85:A2?42B<2?'2D292B:2D2E36B2A2CE9E'2D292B:C69:?882 >6>:=:<:6?6B8:I2?8C2?82D36C2B'6?EBED3636B2A2A6?6=:D:2?CE9E5: A6B>E<22?'2D292B:C6<:D2B L A2<29?523:C2>6?5E823282:>2?2 42B2:=>EG2?D6BC63ED>6?89:DE?8CE9E'2D292B:"2=>6?2B:<=2:??I2252=29 B25:2C:I2?85:A2?42B<2?'2D292B: A2<29C:?2B'2D292B:A252C:2?892B: 5:2?882A36B3292I2328:<E=:D5:<2B6?2<2?B25:2C:?I2=63:9D:?88:A2<29 9E3E?82?2?D2B2B25:2C:I2?85:A2?42B<2?52?CE9E'2D292B:

*6BD2?I22?A6BD2?I22?D6BC63ED52A2D?52;2G23C6D6=29?52 >6>292>: <@?C6A B25:2C: 36?52 9:D2> 2=2> 323 :?: ?52 2<2? >6?52A2D<2? 3636B2A2 76?@>6?2 2=2> I2?8 C636?2B?I2 >6BEA2<2? 2A=:<2C:52B:<@?C6A7:C:<2

Matahari merupakan sumber energi yang utama bagi Bumi. Matahari memberikan energi melalui radiasi gelombang yang dipancarkannya.

Bab

7

A. Pengertian Radiasi Benda Hitam

1. Radiasi Benda Hitam

?52D6=2936=2;2B5:<6=2C1D6?D2?8A2?42B2?2D2EB25:2C:@=69 CE2DE 36?52 ':C2=?I2 9E3E?82? 2?D2B2 32?I2<?I2 6?6B8: I2?8 5:A2?42B<2?52?CE9EI2?85:>:=:<:CE2DE36?52 ,642B2C656B92?2?52 52A2D >6=2<E<2? A6?82>2D2? >6=2=E: C63E29 <68:2D2? I2?8 C6B:?8 5:=2<E<2? ':C2=?I2<6D:<2?5236B@=29B282A252A28:92B:I2?846B29 ?52 2<2? >6B2C2<2? 252?I2 <2=@B I2?8 5:A2?42B<2? @=69 4292I2 '2D292B:<6DE3E9 %6D:<2?52>2CE<<652=2>BE2?82?2<2?D6B2C2 329G2CE9EBE2?82?>6?:?8<2D "2=D6BC63ED>6?E?;E<<2?252?I2<2=@B I2?85:A2?42B<2?52B:DE3E9>ED6B9252A=:?8<E?82?56?82?42B2B25:2C: @?D@9D6BC63ED>6>3E<D:<2?329G236?522<2?>6>2?42B<2? B25:2C:6=6<DB@>28?6D:<;:<2>6>:=:<:CE9ED:?88: +25:2C:6=6<DB@>28?6D:< I2?85:A2?42B<2?@=6936?525:C63ED+","-+&%

-29E<29?522A2I2?85:>2<CE556?82?36?529:D2>'!"-& %!,.-.,",-&1' )-&'1+),&.+","$%(+1' &' '" '-.,",-&-+,.- ,EA2I2?5252A2D=63:9>6>292>:D6?D2?8 36?529:D2>A6B92D:<2?82>32B36B:<ED

*252&2'&65:A6B=:92D<2?C63E29<@D2<I2?8D6B3E2D52B:=@82> I2?852A2D5:2?882AC63282:36?529:D2>C6>AEB?252?C2=29C2DEC:C:?I2 5:3E2D=E32?8 292I2I2?8>2CE<>6=2=E:=E32?85:A2?DE=<2?D6BEC >6?6BEC@=695:?5:?8<@D2<52?92>A:B52A2D5:A2CD:<2?D:52<252=28: 4292I2I2?8<6=E2B #?:2BD:?I2=E32?8D6=2936B7E?8C:>6?I6B2AC6>E2 B25:2C: <2=@B I2?8 252 +25:2C: 4292I2 I2?8 <6=E2B 52B: 52=2> <@D2< 9:D2>>6=2=E:C63E29=E32?836B2C2=52B:@C:=2D@B@C:=2D@B92B>@?:<I2?8 36B86D2B5:52=2><@D2<56?82?>@5EC86D2BD6BD6?DE D@>2D@>A252 5:?5:?8<@D2<2<2?>6?I6B2A6?6B8:A2?2C52?36B86D2B D@>2D@>:?: 2<2?36B=2<EC63282:@C:=2D@B92B>@?:<I2?8>6?:>3E=<2?86=@>32?8 6=6<DB@>28?6D:< !6=@>32?8 6=6<DB@>28?6D:< I2?8 5:D:>3E=<2? @=69 @C:=2D@B 2<2? 5:A2?DE=<2? 36BE=2?8E=2?8 @=69 5:?5:?8 <@D2< 52? >6>36?DE<86=@>32?836B5:B:

"2C:= 6<CA6B:>6? >6?E?;E<<2? 329G2 :?D6?C:D2C B25:2C: D6B>2= 36B32?5:?8=EBEC56?82?A2?8<2D6>A2DCE9E36?52 ,6>2<:?D:?88:CE9E C63E2936?52C6>2<:?36C2BAE=26?6B8:<2=@BI2?85:A2?42B<2? ,6=2:? :DE6?6B8:<2=@B52?:?D6?C:D2CB25:2C:D6B>2=C2?82D36B82?DE?8A252 <@?5:C:36?DE<52?A6B>E<22?I2?85:>:=:<:36?52 '6?EBED!8*+&3

418>2&33:?D6?C:D2CB25:2C:D6B>2=CE2DE36?525:?I2D2<2?56?82?

M

Gambar 7.1

Cahaya yang masuk ke dalam kotak yang dianggap sebagai benda hitam sempurna, akan dipantulkan terus-menerus oleh dinding kotak.

!*'*1922*25*1&/&6.0437*5 &).&7.*3)&.8&20*6/&0&31&-74&174&1'*6.098)&1&2'9091&8.-&3

Tes Kompetensi Awal

$:<2?52>6?;6>EB5E2<2:?32C29I2?836BG2B?2 9:D2> 52? AED:9 5: 32G29 C:?2B '2D292B: <2:? >2?2<29I2?82<2?=63:946A2D<6B:?8$6=2C<2? >6?82A256>:<:2?

A2I2?85:>2<CE556?82?36?529:D2>C6>AEB?2

A2<29C6D:2A36?52C6=2=E>6>2?42B<2?6?6B8: A2I2?85:>2<CE55E2=:C>686=@>32?8A2BD:<6= A2I2?85:>2<CE5676<7@D@=:CDB:<52?676<@>AD@?

,63E2936?52>6>:=:<:CE9EC636C2BL $:<2<@?CD2?D26>:C:F:D2C36?52D6BC63ED

D6?DE<2?:?D6?C:D2CB25:2C:I2?85:A2?42B<2?

&;&'

:<6D29E:%%

PM_0>%

6B52C2B<2?*67&2&&3?2<2?5:A6B@=69 _PM_0>%%

0>

$25::?D6?C:D2CB25:2C:D6B>2=I2?85:A2?42B<2?36?52D6BC63ED252=29 0>

%2G2DCA:B2==2>AEA:;2B>6>:=:<:=E2CA6B>E<22?>>_{52?CE9E?I2 L}

:2?52:<2?329G252B:6?6B8:=:CDB:<I2?85:92?D2B<2?A252=2>AE5:B25:2C:<2? 52=2>36?DE<<2=@B52?<2G2DA:;2B36BC:72DC6A6BD:36?529:D2> 6B2A22>A6B62BEC I2?8>6?82=:B52=2>=2>AEI2?85:9E3E?8<2?56?82?CD@A<@?D2<36BD682?82? /282B=2>AED6BC63ED52A2D36B7E?8C:

%6D6B2?82?

6>:C:F:D2C36?52E?DE<36?529:D2>C6>AEB?2

CE9E%

<@?CD2?D2,D672?@=DJ>2??PM0>%

)=69<2B6?2:?D6?C:D2C252=296?6B8:I2?8I2?85:A2?42B<2?D:2A C2DE2?G2<DE52?D:2AC2DE2?=E2C>2<2:?D6?C:D2CB25:2C:D6B>2=52A2D ;E825:?I2D2<2?C63282:52I2A6BC2DE2?=E2C

52? M

%6D6B2?82?

:?D6?C:D2CB25:2C:D6B>2=0>

52I20

=E2CA6B>E<22?36?52>

6?82?>6?CE3CD:DEC:<2?*67&2&&3? <6*67&2&&3?

>2<252I2B25:2C:I2?85:A2?42B<2?36?522<2?>6>:=:<:A6BC2>22?

M

*252CE9EBE2?8C6<:D2BLB25:2C:D6B>2=I2?85:A2?42B<2?36?52 D:52<52A2DD6B=:92D@=69>2D2 <2?D6D2A:36?5236?52D6BC63EDA252 CE9E L 52A2D D6B=:92D "2= D6BC63ED 5:C6323<2? 36?5236?52 :DE >6>2?DE=<2?4292I2 $25:;:<2?52:?8:?>6?82>2D:B25:2C:D6B>2= C2;2 92BEC >6?88E?2<2? 36?52 I2?8 D:52< >6>2?DE=<2? 4292I2 >:C2=?I2 36?5236?52 I2?8 36BG2B?2 9:D2> 6?52 9:D2> >6?I6B2A C6=EBE9B25:2C:I2?852D2?8<6A252?I2 "2=:?:52A2D?522>2D:<6D:<2 C6C6@B2?8>6>2?2C<2?C632D2?836C: *252CE9E5:32G29L36=E> D2>A2<CA6<DBE>G2B?2I2?85:D:>3E=<2?52B:36C::DEC6D6=29CE9E 5:?2:<<2? 52? 36C: >E=2: >6>32B2 2<2? >E=2: D2>A2< A6BE3292? CA6<DBE>G2B?236BC2>22?56?82?<6?2:<2?CE9E

Contoh

7.1

Contoh

7.2

Dalam kehidupan sehari-hari tidak ada benda yang dapat menyerap seluruh radiasi yang mengenainya.

Ingatlah

Dalam SI, suhu menggunakan satuan derajat Kelvin.

2. Spektrum Radiasi Benda Hitam

$:<2CE2DE36?52A252D5:A2?2C<2?36?52D6BC63ED2<2?>6>2? 42B<2?B25:2C:<2=@B52=2>36?DE<CA6<DBE>86=@>32?86=6<DB@>28?6D:< 56?82?A2?;2?886=@>32?852?7B6<E6?C:I2?836B3652 *252CE9EI2?8 =63:9D:?88:2<2?D6B52A2DB25:2C::?7B2>6B29I2?8D:52<52A2D5:=:92D D6D2A:52A2D5:B2C2<2?A2?2C?I2 "2=:?:52A2D5:2>2D:A252C6A@D@?8 =@82>I2?85:A2?2C<2?9:?882>6?42A2:CE9E % &@82>36BA:;2B 56?82?G2B?2<E?:?82D2E<6AED:9AED:92? +25:2C:86=@>32?8I2?8 5:A2?42B<2?<6>E5:2?5:=6G2D<2?>6=2=E:46=29282B5:A6B@=6936B<2C 86=@>32?8I2?8C6>A:DC6A6BD:D2>A2<A252&2'&6

6?82? 56>:<:2? 86=@>32?8 2<2? D6B5:CA6BC: >6?EBED A2?;2?8 86=@>32?8C6D:2ACA6<DBE> 6D6<D@BI2?8D6B=:92DA25282>32B52A2D 5:86C6B86C6B>6?EBEDCE5ED56F:2C:86=@>32?8D6B5:CA6BC: *6B4@322? :?:5:=2<E<2?A252CE9E36?529:D2>I2?836B36523652 *6?82>2D2? A252:?D6?C:D2CCA6<DBE>B25:2C:>6?892C:=<2?52D2I2?85:DE?;E<<2?

A252&2'&6

&2'&6>6?E?;E<<2?329G22A23:=2CE9ECE2DE36?52D6BEC

5:?2:<<2?:?D6?C:D2CB6=2D:752B:CA6<DBE>4292I2I2?85:A2?42B<2??I2 36BE329 #?:>6?I6323<2?A6B86C6B2?52=2>G2B?2G2B?:CA6<DBE>I2?8 D6B2>2D:I2?852A2D5:8E?2<2?E?DE<>6?2<C:BCE9ECE2DE36?52 -6B=:92D ;E82A6B86C6B2?A2?;2?886=@>32?8>2<C:>E>_>2<C ,6>2<:?D:?88: CE9ECE2DE36?52_>2<CC6>2<:?36B86C6B<62B29A2?;2?886=@>32?8 I2?8=63:9A6?56<

82B?52=63:9>6>292>:"E<E>*6B86C6B2?0:6?A6B92D:<2?

&2'&636B:<ED

Gambar 7.3

Spektrum warna pijar suatu benda panas berubah terhadap suhunya.

Gambar 7.2

Percobaan untuk mengamati spektrum radiasi benda hitam.

Warna

1.500

1.400

1.300

1.200

1.100

1.000

900

800

700

600

500

putih

kuning muda

kuning

oranye

merah-oranye

merah ceri

merah tua

baru tampak T ºC

I (Wb/m2₎

(m)

T₂ > T₁

T₁

benda hitam

prisma celah

spektrum gelombang

detektor

Gambar 7.4

Grafik pergeseran panjang gelombang maksimum pada

&;&'

:<6D29E:

=E2CA6B>E<22?>>_PM_>CE9E>ED=2<%

%6>:C:F:D2C2?882A36?529:D2> PM0>% 2I2<2=@BB25:2C:I2?85:A2?42B<2?@=69=2>AEA:;2B5:9:DE?8>6=2=E:*67&2&&3 ?I2:DE

PM_03>%PM_>%0

2I2<2=@BB25:2C::?:252=2952B:52I2=:CDB:<I2?85:36B:<2?<6=2>AEA:;2B $25:0P=:CDB:<=:CDB:< 0 0

-682?82?=:CDB:<F@=D

BEC=:CDB:<I2?8>6?82=:B>6=2=E:=2>AEA:;2B5:9:DE?852B:BE>EC52I2=:CDB:<

0

/

2B:&2'&6 D6B=:92D 329G2 A2?;2?8 86=@>32?8 :?D6?C:D2C >2<C:>E> 36?52 I2?8 CE9E?I2 D:?88: =63:9 A6?56< 52B: A2?;2?8 86=@>32?8:?D6?C:D2C36?52I2?8CE9E?I2B6?529 !6;2=2A6B86C6B2?_>2<C A252 B25:2C: 36?52 9:D2> 5:C63ED "E<E> *6B86C6B2? 0:6? ,642B2 >2D6>2D:C "E<E> *6B86C6B2? 0:6? 5:?I2D2<2? 52=2> A6BE>EC2? 36B:<ED

_>2<C<@?CD2? M

0:6?>6?6>E<2?329G292C:=<2=:2?D2B2_>2<C52?CE9E>ED=2< >6BEA2<2?3:=2?82?<@?CD2?C6A6BD:A252*67&2&&3?52?3:=2?82? <@?CD2?A252A6BE>EC2?"E<E>*6B86C6B2?0:6?36B?:=2:PM_>%

"E<E>*6B86C6B2?0:6?;E825:8E?2<2?E?DE<>6>A6B<:B2<2?CE9E C63E29 3:?D2?8 56?82? >6=:92D G2B?2 4292I2 C63E29 3:?D2?8 CE9E 3:?D2?8D6BC63ED52A2D5:AB65:<C:<2?

Contoh

7.3

,63E2936?525:A2?2C<2?9:?88236BCE9E L -6?DE<2?=29A2?;2?886=@>32?8 >2<C:>E>B25:2C:D6B>2=I2?85:A2?42B<2?36?52D6BC63ED

&;&'

:<6D29E: L % % 36B52C2B<2?*6BC2>22?M2<2?5:A6B@=69

_>2<C>2<C %PM>%

>2<C >% >_%

$25:A2?;2?886=@>32?8>2<C:>E>B25:2C:D6B>2=252=29PM_>

I

T1 T₂

T₃

6B52C2B<2?8B27:<:?D6?C:D2CB25:2C: D6B9252A A2?;2?8 86=@>32?8 C6A6BD: 5:DE?;E<<2?A25282>32B5:C2>A:?8 3282:>2?2<299E3E?82?2?D2B2CE9E>ED=2< 52?

&;&'

2B:8B27:<A25282>32B5:C2>A:?85:A6B@=69

329G2EBED2?A2?;2?886=@>32?8E?DE<:?D6?C:D2CB25:2C:>2<C:>E>252=29

& & &

6B52C2B<2?9E<E>A6B86C6B2?0:6?*67&2&&3?5:A6B@=69

&

2D2E _&

$25:&& &

5:A6B@=69

Contoh

7.4

3. Pendekatan Teori Rayleigh–Jeans

*252 D29E? >E?4E= A6BD2?I22? 3282:>2?2 >6?;6=2C<2? CA6<DBE>B25:2C:36?529:D2> *6?82>2D2?52?6<CA6B:>6?I2?8D6=29 5:=2<E<2?A252>2C2:DE>6?4@32>6?42B:A6?;6=2C2? ,A6<DBE>B25:2C:

Tokoh

Max Planck

(1858 – 1947)

Max Planck dilahirkan di Kiel, Jerman. Ia belajar di Munich dan Berlin. Seperti banyak ahli fisika lainnya, ia seorang pemain musik yang pandai. Pada tahun 1900 M, setelah 6 tahun belajar di Universitas Berlin, ia menyatakan bahwa kunci pemahaman radiasi benda hitam adalah anggapan bahwa pemancaran dan penyerapan radiasi terjadi dalam kuantum energi hf. Penemuan yang menghasilkan hadiah Nobel 1918 ini sekarang dianggap sebagai tonggak dari fisika modern. Walaupun selama Hitler berkuasa, ia tetap tinggal di Jerman. Ia memprotes perlakuan Nazi kepada ilmuwan Yahudi dan sebagai akibatnya ia harus melepaskan kedudukannya sebagai presiden Institut Kaiser Wilhelm. Setelah perang dunia kedua, institut tersebut diberi nama Institut Planck dan ia kembali menjabat sebagai presiden sampai akhir hayatnya.

Sumber: Fundamental Of Physics, 2001

36?529:D2>5:D6B2?8<2?@=6946) &=1*.,-M52?!.6&2*7

45;&6) *&37M *6BE>EC2?>6B6<2>6?88E?2<2?D6@B:

7:C:<2<=2C:<C6A6BD:D6@B:<:?6D:<82C

:%6=2C1#?52D6=29>6>A6=2;2B:>2D6B:A2?2C36?5236B9E3E?82? 56?82?6?6B8:<:?6D:<>@=6<E=82C -6@B:6<:A2BD:C:>6?I2D2<2?329G2 6?6B8:D@D2=82C52=2>CE2DEBE2?82?D6BDEDEA5:328:C642B2>6B2D2<6 C6D:2A>@=6<E=I2?8D6B52A2D5:52=2>BE2?82? $:<26?6B8:D@D2=C:CD6> 252=2952?32?I2<?I2>@=6<E=I2?836B25252=2>BE2?82?252=29 6?6B8:B2D2B2D2I2?85:>:=:<:@=69C6D:2A>@=6<E=252=29 ?6B8::?: D6B<2?5E?852=2>36?DE<6?6B8:<:?6D:<C6D:2A>@=6<E= <2?D6D2A:D:52< 36B2BD:C6>E2>@=6<E=>6>:=:<:6?6B8:I2?8C2>2I2:DE (:=2:D6BC63ED 92?I2=29>6BEA2<2??:=2:B2D2B2D2

&2'&6 >6>A6B=:92D<2? C632B2? <646A2D2? I2?8 5:>:=:<: >@=6<E= 82C ,632B2? 6?6B8: <646A2D2? <2B6?2 6?6B8: <:?6D:< C6=2=E 36B9E3E?82?56?82?<646A2D2? &=1*.,-*&37>6=:92D329G2<EBF2 C632B2?:DEC6BEA256?82?92C:=I2?85:A6B@=69A252:?D6?C:D2CCA6<DBE> B25:2C:D6B>2= '6B6<236B2?882A2?252<6>:B:A2?2?D2B2C:72DA2?2C 36?5252?B25:2C:D6B>2= 6?82?A6?56<2D2?I2?8>6B6<2=2<E<2?

&=1*.,-*&37 >6>A6B@=69 A6BE>EC2? 329G2 :?D6?C:D2C B25:2C:

36B32?5:?8D6B32=:<56?82?A2?8<2D6>A2DA2?;2?886=@>32?8 .?DE< I2?8 36C2B :?D6?C:D2C 2<2? C6>2<:? <64:= A23:=2 >6?56<2D:D2<9:?882:?D6?C:D2C2<2?>6?56<2D: ?@= "2= :?: C6CE2: 56?82?92C:=6>A:B:C <2?D6D2A:2A23:=2>6?56<2D:?@=92=:?:C2?82D >6?I:>A2?8 52B: 92C:= 6>A:B:C I2?8 >6?E?;E<<2? 329G2 :?D6?C:D2C >6?56<2D:?@=<6D:<2C6>2<:?>6?864:=

*6?I:>A2?82? A6BC2>22? +2I=6:89$62?C I2?8 C2?82D ;2E9 :?: 5:?2>2<2?N6?42?2.=DB2/:@=6DO<2B6?2 I2?8<64:=36B25252=2> G:=2I2986=@>32?8E=DB2F:@=6D

&2'&6 >6?E?;E<<2? 9E3E?82? :?D6?C:D2C 52? A2?;2?8

86=@>32?82?D2B2<EBF2+2I=6:89$62?C52?<EBF20:6? -6@B:%.*3

52A2D>6?6B2?8<2?CA6<DBE>A252A2?;2?886=@>32?8I2?8A6?56< D6D2A:>6?I:>A2?8<6D:<2>6?6B2?8<2?A2?;2?886=@>32?8I2?8A2?;2?8 ,632=:<?I2 D6@B: &=1*.,-*&37 52A2D >6?6B2?8<2? CA6<DBE> A252 A2?;2?886=@>32?8I2?8A2?;2?8D6D2A:>6?I:>A2?8<6D:<2>6?6B2?8<2? A2?;2?886=@>32?8I2?8A6?56<

4. Teori Planck

-6@B: <=2C:< D6?D2?8 4292I2 C63282: 86=@>32?8 6=6<DB@>28?6D:< 52A2D>6?;6=2C<2?52B:>2?22C2=B25:2C:<2=@BD6D2A:D:52<3:C256?82? D6A2D>6>AB65:<C:<2?CA6<DBE>4292I2I2?85:A2?42B<2?C63282:>2?2 I2?8D6B2>2D:@=69%.*3 -6@B:%.*3>2>AE>6?;6=2C<2?B25:2C:36?52 9:D2>E?DE<A2?;2?886=@>32?8I2?8A6?56<D6D2A:8282=E?DE<A2?;2?8 86=@>32?8 I2?8 A2?;2?8 ,632=:<?I2 D6@B: &=1*.,-*&37 36B92C:= >6?;6=2C<2?B25:2C:36?529:D2>E?DE<A2?;2?886=@>32?8I2?8A2?;2?8 D6D2A:8282=E?DE<A2?;2?886=@>32?8I2?8A6?56<

<9:B?I2A6?;6=2C2?I2?8>6>E2C<2?=29:B52B:C6@B2?87:C:<2G2? $6B>2?&<1&3(0M #2>6?4@32>6=2<E<2?A6?56<2D2? =2:?56?82?>6?82;E<2?CE2DEBE>EC6>A:B:C52?D6B?I2D2C2?82D4@4@< 56?82?92C:=A6?82>2D2??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.

1&3(0 >6?42B: 52C2B D6@B: E?DE< BE>EC 6>A:B:C?I2 E2 3E=2? <6>E5:2?:236B92C:=>6>3E2D2CE>C:I2?8C2?82D>6?86;ED<2?A252 C22D:DEI2:DED6?D2?886D2B2?>@=6<E=>@=6<E=5:A6B>E<22?36?52 9:D2> 1&3(0>6?86>E<2<2?A@CDE=2D?I2C63282:36B:<ED

?6B8: B25:2C: I2?8 5:A2?42B<2? @=69 86D2B2? >@=6<E=>@=6<E= @C:=2D@B36?52>6BEA2<2?A2<6DA2<6D<E2?D26?6B8: 6C2B?I2 6?6B8:52=2>C6D:2AA2<6D>6BEA2<2?<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?DE>52?252=297B6<E6?C:86D2B2?>@=6<E=>@=6<E=C652?8 <2?!>6BEA2<2?<@?CD2?D2*=2?4<I2?836C2B?I2PM_$C

)=69 <2B6?2 6?6B8: B25:2C: 36BC:72D 5:C<B:D 5:<2D2<2? 6?6B8:?I2 D6B<E2?D:C2C:52?6?6B8:I2?85:A6B3@=69<2?56?82?' 5:C63EDD:?8<2D6?6B8:

'@=6<E=>@=6<E=>6?I6B2A2D2E>6>2?42B<2?6?6B8:B25:2C:4292I2 52=2>A2<6D5:C<B:DI2?85:C63ED<E2?DE>2D2E7@D@? ?6B8:7@D@? <2B6?2A6B36522?5E2D:?8<2D6?6B8:C6A6BD:D2>A2<A252&2'&6 252=29

! M

$:<2 >@=6<E=>@=6<E= >6?I6B2A>6>2?42B<2? 7@D@? D:?8<2D 6?6B8:?I236BD2>3292D2E36B<EB2?8C636C2B! !282C2?1&3(0:?: 36B=2<EE?DE<36?529:D2>

&2?8<291&3(056?82?A@CDE=2D?I2329G26?6B8:@C:=2D@BD6B<E2?D:C2C: >6BEA2<2?C63E29D6B@3@C2?36C2B1&3(0C6?5:B:36BC2>2:=>EG2? C62?8<2D2??I2D:52<>6?I252B:92=:DE !282C2?*=2?4<5:2?882AC63282: D@?882<2G2=7:C:<2<E2?DE>

E n

0 1 2 3 4 ke n =

0 1hf

2hf

3hf

4hf

Gambar 7.7

Tingkat-tingkat energi yang diperkenankan untuk satu molekul yang frekuensinya f.

$E>=29>:?:>E>7@D@?4292I2I2?8A2?;2?886=@>32?8?I2?>E?DE< >6?:>3E=<2?B2?8C2?82?F:CE2=A252>2D2?@B>2=252=29'7@D@?A6BC6<@? $:<246A2DB2>32D4292I2P_>C52?!PM_{$CD6?DE<2?=2952I2}

4292I2D6BC63ED

&;&'

?6B8:4292I236B52C2B<2?*67&2&&3?252=29

' ! ' !

2I24292I2D6BC63ED52A2D5:D6?DE<2?C63282:36B:<ED ' !

- -

$C >C ₀

C >

Contoh

7.5

Tantangan

untuk Anda

5. Aplikasi Radiasi Benda Hitam untuk Mengukur Suhu

Matahari

'2D292B: >6BEA2<2? 3:?D2?8 I2?8 A2=:?8 56<2D 56?82? E>: ;2B2<?I2C6<:D2B <> '2D292B:>6>2?42B<2?6?6B8:<2=@B I2?8C2?82D36B8E?2328:<69:5EA2?5:E>: ?6B8:D6BC63ED36B2C2= 52B: B62<C: 7EC: 9:5B@86? 5: 52=2> :?D: '2D292B: 2A2D<29 ?52 >6>32I2?8<2?36B2A236C2B6?6B8:I2?85:92C:=<2?'2D292B:C69:?882 C2>A2:;2B2< <>6?6B8::DE>2C:925236BEA24292I252? <2=@B

+25:2C:6?6B8:'2D292B:C2?82D36C2BC6A6BD:I2?8D6=29?52A6=2;2B: #?D6?C:D2CB25:2C::?:36B32?5:?8=EBEC56?82?A2?8<2D6>A2DCE9E?I2 '6?EBEDD6@B:B25:2C:I2?85:A2?42B<2?:?:>6>:=:<::?D6?C:D2CI2?8 36B36523652 .?DE<=63:9>6>292>:<@?C6A:?:A6B92D:<2?&2'&6 36B:<ED:?:

&2'&6>6?E?;E<<2?CA6<DBE>B25:2C:'2D292B:I2?85:E<EB 5:=E2B2?8<2C2 !B27:<D6BC63EDC2?82D>:B:A56?82?8B27:<:?D6?C:D2C B25:2C:36?529:D2> )=69<2B6?2:DEA2B22CDB@?@>>6?82CE>C:<2? '2D292B:C63282:36?529:D2>C69:?8823:C25:9:DE?836B2A2CE9E5: A6B>E<22?'2D292B:56?82?>6?88E?2<2?"E<E>*6B86C6B2?0:6? 2B: 8B27:< D6B=:92D 329G2 ?:=2: :?D6?C:D2C >2<C:>E> D6B52A2D A252 A2?;2?886=@>32?8C636C2B K526B29A2?;2?886=@>32?8C:?2B D2>A2< '6?EBED"E<E>*6B86C6B2?0:6?2<2?5:52A2D<2??:=2:CE9E 5:A6B>E<22?'2D292B:C63282:36B:<ED

>2<C

PM>%

P >% P >

%

,6=2:?E?DE<>6?8E<EBCE9E'2D292B:A6?6B2A2?B25:2C:36?52 9:D2>:?:52A2D5:8E?2<2?E?DE<>6?8E<EBCE9E3:?D2?8=2:??I2I2:DE 56?82?>6?82?2=:C:CCA6<DBE>3:?D2?8D6BC63ED

Gambar 7.8

Grafik intensitas radiasi Matahari yang diukur di luar

angkasa.

I(W/m2₎

_{10 m}7

,2=29C2DE:CE8=@32=I2?8C6B:?85:2?8<2D@=692<D:F:D2C=:?8<E?82?9:5EA252=29 :CE D6?D2?8 A6>2?2C2? E>: 52 C6328:2? ?682B2 >2;E I2?8 D:52< >2E >6?2?52D2?82?:+(-($(%1(-(D6?D2?8A6>32D2C2?<252B6>:C:82C52B::?5ECDB: !2C6>:C::?:C6328:2?36C2B252=29) '6?EBEDA2B229=:82C):?:=29I2?8 >6?82<:32D<2?A6>2?2C2?E>:2D2E5:<6?2=56?82?:CD:=29$.&! +'(.,- 2B:=29:?7@B>2C:52B:36B3282:CE>36B3E<E>2;2=29:?D6B?6D 52?=2:?=2:?D6?D2?89E3E?82?2?D2B2676<BE>29<24252?B25:2C:36?529:D2> :C<EC:<2?=2956?82?D6>2?C6<6=2C?52D6?D2?892=:?:

Mari Mencari Tahu

1 Å = 10–10 _m

Ingatlah

Tantangan

untuk Anda

Grafik pada Gambar 7.8 menunjukkan intensitas radiasi Matahari yang diukur di luar angkasa. Apakah Anda bisa menduga bagaimana grafik intensitas radiasi Matahari jika diukur di permukaan Bumi? Apakah di seluruh tempat di permukaan Bumi intensitas radiasi Matahari selalu sama? Jelaskan jawaban Anda dengan bahasa yang mudah dipahami dan diskusikanlah bersama teman sekelas.

Kata Kunci

Gambar 7.9

(a) Cahaya sebagai gelombang; (b) Cahaya sebagai paket-paket

energi.

3 ,E9E<6B;27:=2>6?DE?8CD6?52=2>CE2DE=2>AEA:;2B

252=29 %52?6>:C:F:D2C?I2 -6?DE<2?=E2C A6B>E<22?7:=2>6?=2>AEA:;2B0

,63E29=E32?8<64:=A2525:?5:?8-'.+>6?I6BEA2: 36?529:D2> $:<2=E2C?I24>_{52?CE9E?I2 L}

C2>2C6A6BD:CE9E5:52=2>D2?EB36B2A2<296?6B8: I2?85:B25:2C:<2?<6=E2B=E32?8C6D:2A56D:< @=2+4>36BC:72DC6A6BD:36?529:D2>36B252

52=2><62522?C6:>32?856?82?=:?8<E?82??I2 -6B?I2D2 3@=2 >6?I6B2A 52I2 <0 52B: =:?8<E?82??I2 6B2A2<29CE9E3@=2:DE

&2>AEA:;2B52A2D5:2?882A36B36?DE<3@=2 $2B:;2B: =2>AEA:;2BA6BD2>2252=295E2<2=:;2B:;2B:=2>AE <65E2 ,E9EA:;2BA6BD2>252?<65E2>2C:?8>2C:?8 L52?L -6?DE<2??:=2:A6B32?5:?82?2?D2B2 52I2<2=@BB25:2C:=2>AEA6BD2>252?=2>AE<65E2

%@?CD2?D26>:C:F:D2CC63E2936?529:D2>252=29 ":DE?8=29:?D6?C:D2CB25:2C:I2?85:A2?42B<2?2A23:=2 CE9E36?52:DE%

,63E293@=2=@82>56?82?;2B:;2B:4>5:A2?2C<2? *252CE9EL3@=2=@82>:DE>6>2?42B<2?B25:2C: 56?82?52I2P_{G2DD ":DE?8=296>:C:F:D2C3@=2}

=@82>D6BC63ED

":DE?8=2952I2I2?85:A2?42B<2?@=69C63E29<E3EC I2?85:A2?2C<2?9:?882L %E3ECD6BC63ED>6>:=:<: A2?;2?8C:C:4>52?D6B3E2D52B:3292?56?82? 6>:C:F:D2C

6?52>6>2?42B<2?B25:2C:56?82?>2H?>

6?52:DED6BEC>6?82=2>:A6>2?2C2?C69:?882 CE9E?I2<2=:=:A2DCE9EC6>E=2 -6?DE<2?=29>2H

C6D6=29A6>2?2C2?

Tes Kompetensi

Subbab

A

*6/&0&31&-5&)&'9091&8.-&3

B. Dualisme Gelombang Partikel

1. Sifat Partikel yang Dimiliki Gelombang

*252>E=2?I232?I2<7:C:<2G2?I2?8>6?82?882A4292I2C63282: 86=@>32?8 "2=:?:5:A6B<E2D56?82?252?I25:7B2<C:A@=2B:C2C:B67B2<C: B67=6<C:52?:?D6B76B6?C:I2?8C6CE2:56?82?C:72DE>E>86=@>32?8 <2? D6D2A:<6D:<2A2B27:C:<2G2?>6?6>E<2?76?@>6?2B25:2C:36?529:D2> 676<7@D@=:CDB:<52?676<@>AD@?2CE>C:4292I2C63282:86=@>32?8D:52< 52A2D>6?;6=2C<2?76?@>6?276?@>6?2D6BC63ED %6>E5:2?>E?4E==29 A2?52?82?329G24292I2252=29A2BD:<6= ,63282:2?2=@8:A6B92D:<29

&2'&6 *25282>32BD6BC63ED?523:C2>6>6B92D:<2?A6B36522?

4292I2;:<25:2CE>C:<2?C63282:86=@>32?852?C63282:A2BD:<6= 6?82? 2CE>C: C63282: 86=@>32?8 4292I2 5:A2?42B<2? C63282: B2>32D2? 86=@>32?8I2?8<@?D:?E 52AE?56?82?2CE>C:C63282:A2BD:<6=4292I2 5:A2?42B<2?52=2>36?DE<A2<6DA2<6D6?6B8:I2?85:C63ED7@D@?

,EA2I2?52=63:9>6>292>:2CE>C:4292I2C63282:A2BD:<6=?52 3:C2>6>A6=2;2B:676<7@D@=:CDB:<52?676<@>AD@?36B:<ED

a. Efek Fotolistrik

#%-+%),'1%$-+('%$-+('+")+&.$')%-%( &$-"$ ","'+"' '+$.',"-+-'-.",.-$(-(%",-+"$ =6<DB@?I2?8D6B=6A2C 52B:A6B>E<22?A=2D=@82>D6BC63ED5:C63ED6=6<DB@?7@D@ *6B:CD:G2:?: A6BD2>2<2=:5:D6>E<2?@=69*68>C6A6BD:5:82>32B<2?A252&2'&6

*6B2?8<2DA6B4@322?E?DE<>6?82>2D:676<7@D@=:CDB:<D6B5:B:2D2C D23E?8<24292>A2E52B252?A=2D=@82>I2?85:C63EDC63282:<2D@56 %6D:<2<2D@565:C:?2B:56?82?C:?2BE=DB2F:@=6D6=6<DB@?2<2?D6B=6A2C 52B:<2D@5652?36B86B2<>6?E;E2?@56C69:?8822BEC>6?82=:BA252 B2?8<2:2? 2?I2<?I26=6<DB@?I2?8D6B=6A2C52A2DD6B=:92D52B::?5:<2D@B <E2D2BECI2?85:DE?;E<<2?@=692>A6B6>6D6B ?6B8:<:?6D:<I2?85:>:=:<: 6=6<DB@? 52A2D 5:D6?DE<2? 56?82? 42B2 >6>A6B36C2B 3652 A@D6?C:2= 2?D2B2<2D@5652?2?@56C69:?8823652A@D6?C:2=36BC:72D>6?292?=2;E

2

Gambar 7.10

Skema eksperimen efek fotolistrik. ruang vakum

cahaya

saklar geser tutup tabung

C

T

i

i

+

– – +

Gambar 7.11

(a) Apabila energi kinetik elektron melebihi energi potensial penghalang, elektron akan dapat mendaki bukit potensial; (b) Energi kinetik elektron tidak bergantung pada intensitas cahaya; (c) Setiap permukaan memiliki frekuensi (f₀) berbeda.

E_k

v

6=6<DB@? 6BC2>22?56?82?<6?2:<2?3652A@D6?C:2=A6?E?;E<2?;2BE> 2>A6B6>6D6B2<2?>6?864:= $:<2A252CE2DE<6D:<2;2BE>2>A6B>6D6B >6?E?;E<2?8<2?@=36C2B?I26?6B8:A@D6?C:2=C2>256?82?36C2B6?6B8: <:?6D:<I2?85:>:=:<:6=6<DB@? (:=2:3652A@D6?C:2=A252C22D:DE5:C63ED A@D6?C:2=96?D:

?6B8:A@D6?C:2=I2?85:36B:<2?52A2D5:AB65:<C:<2?C63282:C63E29

3E<:DI2?892BEC5:=6G2D:6=6<DB@?C6A6BD:A252&2'&6& A23:=2 3E<:DA@D6?C:2=D6BEC5:A6BD:?88:CE2DEC22D2>A6B6>6D6BI2?85:A2C2?8 5:32=:<3E<:D>6?E?;E<<2?2?8<2?@= #?:36B2BD:6?6B8:<:?6D:<6=6<DB@? D:52< 4E<EA =28: E?DE< >6=6G2D: 3E<:D A@D6?C:2= C69:?882 36C2B?I2 A@D6?C:2=96?D:36BC6CE2:2?56?82?6?6B8:<:?6D:<6=6<DB@?

$ M

2D2E

>2<C

&/ M

<CA6B:>6?I2?85:=2<E<2?@=69.378*.356?82?>6?8E329E329 7B6<E6?C:4292I2I2?8;2DE9A252A=2D=@82><2D@56:?D6?C:D2C4292I2 52?A@D6?C:2=A6?892=2?8A252676<7@D@=:CDB:<>6>36B:<2?3636B2A2 <6C:>AE=2?C63282:36B:<ED

2 6C2B6?6B8:<:?6D:<>2<C:>E>6=6<DB@?D:52<36B82?DE?8A252:?D6?C:D2C 4292I2A6B92D:<2?&2'&6'

3 ,6D:2AA6B>E<22?=@82>>6>3EDE9<2?7B6<E6?C:>:?:>E>D6BD6?DEI2?8 5:C63ED7B6<E6?C:2>32?8282B676<7@D@=:CDB:<52A2D36B=2?8CE?8 A6B92D:<2?&2'&6(

4 =6<DB@?6=6<DB@?5:3632C<2?52B:A6B>E<22?=@82>92>A:BD2?A2C6=2?8 G2<DEI2:DE<EB2?852B:M_{C6<@?C6D6=29A6?I:?2B2?}

5 -6@B:86=@>32?8D:52<52A2D>6?;6=2C<2?>6?82A26?6B8:<:?6D:< >2<C:>E>6=6<DB@?36BD2>329;:<27B6<E6?C:4292I25:A6B36C2B "2C:=6<CA6B:>6?D6BC63EDD:52<52A2D5:;6=2C<2?@=69D6@B:<=2C:< D6?D2?886=@>32?86=6<DB@>28?6D:< '6?EBEDD6@B:<=2C:<6?6B8:I2?8 5:<2?5E?886=@>32?86=6<DB@>28?6D:<36BC6CE2:2?56?82?:?D6?C:D2C?I2 A23:=2:?D6?C:D2CC6>2<:?D:?88:6?6B8:86=@>32?86=6<DB@>28?6D:< 2<2? >6?:?88: AE=2 '652? =:CDB:< I2?8 5:32G2 86=@>32?8 6=6<DB@ >28?6D:<2<2?>6>36B:<2?82I2A2526=6<DB@?5:A6B>E<22?=@82> C69:?8826=6<DB@?>6>A6B@=696?6B8:52B:86=@>32?8 $:<26?6B8:I2?8 5:>:=:<:6=6<DB@?4E<EA36C2B6=6<DB@?2<2?D6B=6A2C52B:A6B>E<22? =@82> 6B52C2B<2?92=:DEC692BEC?I26?6B8:<:?6D:<6=6<DB@?36B82?DE?8 A252:?D6?C:D2C4292I2

%6925:B2?7B6<E6?C:2>32?8AE?D:52<52A2D5:;6=2C<2?56?82?D6@B: <=2C:< <CA6B:>6?>6?E?;E<<2?329G2C6<64:=2A2AE?:?D6?C:D2C4292I2 2A23:=27B6<E6?C:?I2=63:936C2B52B:A2527B6<E6?C:676<7@D@=:CDB:< 2<2?D6B;25: '6?EBEDD6@B:<=2C:<C692BEC?I2I2?8252252=29:?D6?C:D2C 2>32?8 6?82? <636B82?DE?82? 6?6B8: 4292I2 A252 :?D6?C:D2C?I2 9E3E?82?=:?62B2?D2B26?6B8:<:?6D:<6=6<DB@?52?7B6<E6?C:86=@>32?8 6=6<DB@>28?6D:<C2>2C6<2=:D:52<52A2D5:;6=2C<2?

'6?EBED1'*68 .378*.3 C6>E2 6?6B8: 7@D@? 5:36B:<2? <6A252 6=6<DB@?52?:?:>6?I6323<2?7@D@?=6?I2A #236BA2?52?82?329G2 <E2?DE>>6BEA2<2?C:72D86=@>32?8:DEC6?5:B: '6?EBED?I24292I2 Sumber: Fisika untuk Sains dan Teknik Tipler

2 3

2

0 4 6 8

f_{0 f}

0 f0

C_e N_a

K

1014 _Hz

energi potensial gelombang (eV)

–V0 V

I

intensitas tinggi intensitas rendah

2

3

4

D6B5:B:2D2CA2<6DA2<6DI2?85:C63EDC63282:7@D@? @D@?7@D@?>6BEA2<2? A2BD:<6=I2?8D:52<36B>2CC2I2?85:C6B2A52?5:A2?42B<2? ?6B8:I2?85:>:=:<: @=697@D@?C2>256?82?<E2?D2I2?85:<6>E<2<2?@=69*=2?4<I2:DE! 56?82?!252=29<@?CD2?D2*=2?4<52?252=297B6<E6?C:86=@>32?8 6=6<DB@>28?6D:<

:?CD6:?52A2D>6?;6=2C<2?C642B2C6>AEB?292C:=676<7@D@=:CDB:< 292I2I2?8;2DE95:2D2C=@82>5:=E<:C<2?C63282:B6?D6D2?7@D@?I2?8 >6?E>3E<A252=@82>C6D:2A7@D@?>6?E>3E<6=6<DB@?52=2>=@82> *252A6B:CD:G2DE>3E<2?D6BC63ED7@D@?>6>36B:<2?C6=EBE96?6B8:?I2 <6A2526=6<DB@?52?7@D@?:DEC6?5:B:>6?;25:=6?I2A

?6B8:I2?85:A6B=E<2?E?DE<>6=6A2C<2?5:B:52B:A6B>E<22?=@82> 5:C63ED7E?8C:<6B;2 .?DE<;6?:C=@82>I2?836B3652D6?DE?I27E?8C: <6B;22<2?36B3652AE=2<2B6?2A6B36522?6?6B8::<2D2?D2B26=6<DB@? 52?:@?52=2>=@82> $25:E?DE<=@82>D6BD6?DE36B=2<E

! M

$:<27B6<E6?C:7@D@?=63:936C2B52B:A2527B6<E6?C:2>32?8<6=63:92? 6?6B8:I2?85:D6B:>26=6<DB@?:DE2<2?>6?;25:6?6B8:<:?6D:<6=6<DB@?

!2!_$ M

!!_$

!_$ M

Keterangan:

! <@?CD2?D2*=2?4<PM_$C

7B6<E6?C:86=@>32?84292I2"J

7B6<E6?C:2>32?8"J

$:<25:3E2D52=2>C63E29D236=7E?8C:<6B;27@D@=:CDB:<3636B2A2;6?:C =@82>3:C25:=:92D52=2>"&'*1

1 eV = 1,6 × 10–19 _J

Ingatlah

"&'*1

E?8C:%6B;2=6<DB@?A252636B2A2&@82>

6C:E> C

%2=:E> %

(2DB:E> (2

>2C E

-6>3282 E

*6B2< 8

*=2D:?2 *D

4,&2 &2'&3, 93,7.*6/&%*$

Efek fotolistrik selain memiliki peranan penting dalam teori foton pada cahaya, juga memiliki banyak sekali aplikasi dalam kehidupan sehari-hari. Sebagai contoh adalah alarm pencuri dan pembuka otomatis yang juga menggunakan sirkuit fotolistrik. Ketika seseorang menghalangi sinar yang dipancarkan, penurunan arus listrik dapat mengaktifkan saklar sehingga bel berbunyi atau pintu terbuka. Biasanya sinar yang digunakan adalah sinar ultraviolet dan inframerah karena kedua sinar ini tidak terlihat.

The photoelectric effect, besides playing an important historical role in confirming the photon theory of light, also has many practical applications. Burglar alarms and automatic door openers often make use of the photocell circuit. When a person interrupts the beam of light, the sudden drop in current in the circuit activates a switch which operates a bell or opens the door. UV or IR light is sometimes used in burglar alarms because of its invisibility.

Sumber: Physics for Scientist & Engineers

Informasi

untuk Anda

Information for You

B6<E6?C:2>32?8CE2DE3292?P_{"J $:<23292?D6BC63ED5:C:?2B:56?82?C:?2B}

I2?8>6>:=:<:7B6<E6?C:P_{"JD6?DE<2?36C2B6?6B8:<:?6D:<6=6<DB@?I2?8}

D6B=6A2C52B:A6B>E<22?=@82>D6BC63ED

&;&'

_$!2!!2

_$PM_$CP"JMP"J

_$PM_$CP"JPM_;@E=6

Contoh

7.6

%2=:E>5:C:?2B:56?82?4292I2E=DB2F:@=6DI2?8A2?;2?886=@>32?8?I2 K $:<27E?8C: <6B;2<2=:E>6/D6?DE<2?=29?:=2:A@D6?C:2=96?D:A252A6B:CD:G2676<7@D@=:CDB:< D6BC63ED!PM_$C

&;&'

:<6D29E: _KPM_>

6/6/PM$C

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?6B8:<:?6D:<>2<C:>E>6=6<DB@?$>!2 ! 2

$>

>C

$C $

>

$_>PM_$

%6>E5:2?8E?2<2?*67&2&&3?C69:?882 $_>2D2E$>

$

/

$25:A@D6?C:2=96?D:A252676<7@D@=:CDB:<D6BC63ED252=29/

b. Efek Compton

2=2>A6B:CD:G2676<7@D@=:CDB:<4292I2I2?85:;2DE9<2?A252<6A:?8 =@82>5:A6B=2<E<2?C63282:A2<6D6?6B8:I2?85:C63ED7@D@? @D@?:DE >6?82=2>:A6B:CD:G2DE>3E<2?56?82?6=6<DB@? :2C2?I2DE>3E<2? C6=2=E5:9E3E?8<2?56?82?>@>6?DE> *252A6B:CD:G2D6BC63ED2<2? 36B=2<E"E<E>%6<6<2=2?'@>6?DE>52?"E<E>%6<6<2=2??6B8: *6?6=:D:2?92>3EB2?C:?2B1I2?85:=2<E<2?68-96425843

M>6?892C:=<2?76?@>6?232BEI2:DEA6B86C6B2?A2?;2?8 86=@>32?82D2EA6BE3292?7B6<E6?C:C636=E>52?C6CE529DE>3E<2? !6;2=2:?:5:;6=2C<2?@=6942584356?82?>6?82?882A329G2I2?8 D6B;25:252=29DE>3E<2?2?D2B2<E2?DE>4292I27@D@?52?6=6<DB@? 3632C %6D:<2 7@D@? >6?E>3E< 6=6<DB@? C6328:2? 6?6B8: 7@D@? 2<2? 5:36B:<2?<6A2526=6<DB@?C69:?8826=6<DB@?>6>:=:<:6?6B8:<:?6D:< 52AE?6?6B8:7@D@?C6D6=29DE>3E<2?2<2?36B<EB2?8 '6?EBEDD6@B: <=2C:<A6?8EB2?82?6?6B8:D:52<2<2?5::<ED:@=69A6BE3292?7B6<E6?C: 2D2EA2?;2?886=@>32?8 (2>E?>6?EBEDD6@B:<E2?DE>A6BE3292? 6?6B8:36B2BD:2<2?D6B;25:A6BE3292?7B6<E6?C:52?A6BE3292?A2?;2?8 86=@>32?8 #?:5:3E<D:<2?52B:92C:=A6?82>2D2?I2?8>6?E?;E<<2? 329G2C6D6=29DE>3E<2?A2?;2?886=@>32?87@D@?36BD2>32936C2B )=69<2B6?26?6B8:7@D@?5:BE>EC<2?C63282: ! ;6=2C=29 329G26?6B8:7@D@?C6D6=29DE>3E<2?2<2?36B<EB2?8

42*3892+4843

%6C6D2B22?>2CC252?6?6B8:>6?EBED.378*.3252=29&_"2=

D6BC63ED2<2??52A6=2;2B:52=2>A@<@<3292C2?36B:<ED?I2C652?8<2?

Contoh

7.7

Foton merupakan paket-paket energi pada cahaya. Konsep ini merupakan kelanjutan dari asumsi cahaya merupakan partikel.

Ingatlah

Tugas Anda 7.2

Proses terjadinya sinar-X merupakan kebalikan dari proses fotolistrik. Carilah informasi dari berbagai sumber tentang sinar-X dan diskusikanlah bersama teman sekelas Anda.

)=69<2B6?2;@E=6PM_{6/36C2B6?6B8:<:?6D:<6=6<DB@?I2?8D6B=6A2C}

252=29

$

>6?EBED*=2?4<4292I236B36?DE<A2<6DA2<6D6?6B8:56?82?6?6B8: 7@D@?C636C2B! 6?82?56>:<:2?A6?56<2D2?C642B2B6=2D:F:CD:< 52A2D5:DE=:C

!

& ! & M

2B:*67&2&&3? ?5252A2D>6>A6B@=69A6BC2>22?>@>6?DE> B6=2D:F:CD:<52B:C63E297@D@?I2:DE

!

) & M

:<6D29E: 52?

>2<2*67&2&&3?52A2D5:DE=:C

2D2E

! !

) ₎

_M

%6D6B2?82?

) >@>6?DE>C63E297@D@?<8>C

46A2DB2>32D4292I2>C A2?;2?886=@>32?84292I2>

! D6D2A2?*=2?4<PM_$C

7B6<E6?C:4292I2"J

*69'&-&3&3/&3,*142'&3,5&)&&2'96&3425843

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6?6B8:>6?;25: :=2:?A:92<C6328:2?6=6<DB@?>6>36?DE<CE5ED 56?82?2B2986B2<7@D@?C636=E>DE>3E<2? "2>3EB2?I2?85:2=2>: @=697@D@?5:C63ED92>3EB2?@>AD@?56?82?4:B:4:B:<92C?I2D6B;25: A6BE3292?52?A6BE3292? .?DE<>6?86D29E:A6BE3292?6?6B8:2D2E A2?;2?886=@>32?87@D@?C6D6=29D6B92>3EB5:8E?2<2?2?2=:C:C56?82? "E<E> %6<6<2=2? '@>6?DE> 52? "E<E> %6<6<2=2? ?6B8: )=69 <2B6?2 6?6B8: I2?8 D6B=:32D C2?82D D:?88: C6BD2 <6>E?8<:?2? 36C2B <646A2D2?6=6<DB@?C6D6=29DE>3E<2?C2?82D36C2BA6BC2>22?5:?2>:<2 I2?85:8E?2<2?252=295:?2>:<2B6=2D:F:CD:<

6?82? >6?88E?2<2? "E<E> %6<6<2=2? ?6B8: 52? "E<E> %6<6<2=2? '@>6?DE> 52=2> 5:?2>:<2 +6=2D:F:CD:< 5:52A2D<2? A6BC2>22?92>3EB2?@>AD@?C63282:36B:<ED

_& ! 4@C

_M

Keterangan:

A2?;2?886=@>32?87@D@?C636=E>DE>3E<2?> ’ A2?;2?886=@>32?87@D@?C6CE529DE>3E<2?>

! D6D2A2?*=2?4<PM_$C

46A2DB2>32D4292I2P_>C

CE5EDA6?I:>A2?82?7@D@?

& >2CC25:2>6=6<DB@?<8

Gambar 7.12

Tumbukan foton dan elektron (a) sebelum tumbukan (b) sesudah tumbukan

foton dengan, p

2

3

', p' foton terha

mbur

elektron terdorong

p_e

v

Tokoh

Arthur Compton (Holly)

(1892–1962)

Arthur Compton adalah seorang ahli Fisika yang dilahirkan di Wooster, Ohio, USA. Dia belajar di Universitas Princetion dan lulus menjadi profesor Fisika di Chicago (1923). Dia meneliti dan menjelaskan Efek Compton, penambahan panjang gelombang sinar-X yang

dihamburkan ketika bertumbukan dengan elektron. Untuk sumbangan pemikirannya tersebut, dia

mendapat penghargaan Nobel Fisika pada 1927.

Sumber:www.allbiographies.com

Ek (eV)

f (Hz) 0,2

3,7

f₀

,:?2B156?82?A2?;2?886=@>32?8_{?>5:92>3EB<2?@=69C63E2932=@<<2B3@?}

,:?2B1I2?85:92>3EB<2?5:2>2D:>6?I:>A2?8LD6B9252A2B29?I2C6>E=2 ":DE?8 A2?;2?886=@>32?8C:?2B1I2?85:92>3EB<2?:?:

&;&'

652A2?;2?886=@>32?87@D@?C636=E>52?C6CE5295:92>3EB<2?52A2D5:9:DE?856?82?

*67&2&&3?

_&! 4@C

:<6D29E:?>!PM_$C52?&PM_<8

>2<2

$C _4@C

<8 >C

PM_>?>

*2?;2?886=@>32?87@D@?C:?2B1I2?85:92>3EB<2?252=29

’_?>?>?>

2. Sifat Gelombang pada Partike

l

*252A6>3292C2?C636=E>?I2D6=295:;6=2C<2?329G286=@>32?8 >6>:=:<:C:72DA2BD:<6= ,6<2B2?8>E?4E=A6BD2?I22?2A2<29A2BD:<6= >6>:=:<: C:72D 86=@>32?8 2=2> A6B:CD:G2 :?D6B76B6?C: 52? 5:7B2<C: 4292I2C:72D86=@>32?84292I2=63:9>6?@?;@=52B:A252C:72DA2BD:<6= 4292I2 52AE?52=2>A6B:CD:G2676<7@D@=:CDB:<52?676<@>AD@?C:72D A2BD:<6=4292I2=63:9>6?@?;@=52B:A252C:72D86=@>32?84292I2

*252 :C:<2G2?36B<632?8C22?*B2?4:C49.7)*64,1.*252=29 @B2?8A6BD2>2I2?8>6?82;E<2?9:A@D6C:C329G2A2BD:<6=C6A6BD:6=6<DB@? ;E8252A2D36BC:72DC63282:86=@>32?8

a. Panjang Gelombang de Broglie

49.7)*64,1.*>6?I2D2<2?329G26=6<DB@?I2?836B86B2<252

<6>E?8<:?2?>6>:=:<:C:72D86=@>32?856?82?A2?;2?886=@>32?8I2?8 C6CE2: *2BD:<6=I2?836B86B2<56?82?<646A2D2?/>6>:=:<:>@>6?DE>

)&/2D2EC642B2B6=2D:F:CD:<5:DE=:C<2?C63282:36B:<ED

! )

)=69<2B6?2

_>2<2

! ! ) C69:?882A2?;2?886=@>32?856B@8=:6252=29

! ! ) &/

_M

*252*67&2&&3 ?CE<E

!

& 5:C63ED;E82A2?;2?886=@>32?8

@>AD@??:=2:?I2252=29

$C _>

<8 >C _& !

Contoh

7.8

Pembahasan Soal

Grafik di atas menunjukkan hubungan antara energi kinetik maksimum elektron terhadap frekuensi foton pada efek fotolistrik. Jika h = 6,6 × 10–34 _{Js dan}

1 eV = 1,6 × 10–19 _{J, besar f adalah ....}

a. 48 × 1014 _Hz

b. 21 × 1014 _Hz

c. 14 × 1014 _Hz

d. 9,5 × 1014 _Hz

e. 8,9 × 1014 _Hz

UMPTN 1996

Pembahasan

Menurut persamaan efek fotolistrik

E_k = hf – W maka

f = EkW

h

Dari grafik, nilai Ek = 0,2 eV = 0,2 (1,6 × 10–19) J

Pada saat f = 0, berlaku

E_k = – W atau W = –E_k

Dari grafik, saat f = 0, nilai E_k = –37 eV, maka W = 3,7 eV = 3,7 (1,6 × 10–19_{) J}

Jadi,

f = Ek W_h =

19

34

0,2 3,7 1,6 10 J 6,6 10 Js

= 9,5 × 1014 _Hz

%6D6B2?82?

A2?;2?886=@>32?8A2BD:<6=>6?EBED56B@8=:6>

! D6D2A2?*=2?4<PM_$C

& >2CC25:2>A2BD:<6=<8

/ =2;EA2BD:<6=>C

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36B2A236C2BI2?892BEC5:36B:<2?&PM_<8PM_52?

!PM_$C

&;&'

,63E296=6<DB@?I2?85:A6B46A2D56?82?3652A@D6?C:2=52B:<62522?5:2>2<2? >6?6B:>2)=:CDB:<52?>6?8E329?I2>6?;25:$6=6<DB@? &/C69:?88236B=2<E

&/ 2D2E/ &

*2?;2?886=@>32?856B@8=:66=6<DB@?252=29

! ! ! !

& / _& & & & &

82BKPM_{>>2<252A2D5:9:DE?8C63282:36B:<ED}

$C >

<8 /

PM_>PM_<8PM_PM_$C

F@=D

Contoh

7.10

Tokoh

Louis Victor de Broglie

(1892–1987)

Louis Victor De Broglie (1892– 1987) lahir di Dieppe, Prancis, dan bersekolah di Sorbonne. Ia

melanjutkan kuliahnya di Universitas Paris tahun 1926. Pada 1929, ia menerima hadiah Nobel dalam bidang Fisika atas teorinya mengenai sifat gelombang pada partikel. Teori ini menjadi dasar dari mekanika kuantum, cabang dari ilmu Fisika. Pada awal 1800, para fisikawan percaya bahwa cahaya terdiri atas gelombang energi. Pada 1900, Max Planck menunjukkan bahwa cahaya dapat bersifat partikel. Pada 1924, de Broglie menyatakan bahwa elektron dapat bersifat sebagai partikel dan gelombang.

Sumber:Conceptual of Physics,2000

Tantangan

untuk Anda

Efek Compton diaplikasikan dalam dunia kedokteran untuk mendeteksi kepadatan tulang. Dengan bahasa Anda sendiri, dapatkah Anda menjelaskan cara kerjanya?

Contoh

7.9

-6?DE<2?A2?;2?886=@>32?856B@8=:6E?DE<36?5236B:<ED:?: 2 @=256?82?>2CC2<8I2?836B86B2<56?82?<646A2D2?>C 3 =6<DB@?I2?836B86B2<56?82?6?6B8:<:?6D:<6/

&;&'

:<6D29E:&<8/>C

2

$C

_>

<8 >C

! & /

3 $=6/PM$

$ <8 $

) &

_<8>C

$C _>

<8>C !

)

b. Eksperimen Davisson-Germer

*252&:.774352?*62*6>6=2<E<2?A6?6=:D:2?

>6?86?2:92>3EB2?6=6<DB@? '6B6<2>6?;2DE9<2?36B<2C6=6<DB@?I2?8 >6>:=:<:6?6B8:<:?6D:<D6BD6?DE<62D2C<B:CD2=DE?882=?:<6= '6B6<2 >6?82>2D:329G2A252CE5EDD6BD6?DED6B;25:D:D:<>2<C:>E>I2?8 36B9E3E?82?56?82?A@=2:?D6B76B6?C: 6B52C2B<2?52D2I2?85:A6B@=69 A2?;2?886=@>32?8I2?85:52A2D<2?D6B?I2D2252<6C6CE2:2?2?D2B2 92C:=I2?8>6B6<2A6B@=6952?A2?;2?886=@>32?8 I2?85:52A2D<2? >6?EBED 9:A@D6C:C 56 B@8=:6 ,<6>2 2=2D A6B4@322? I2?8 5:=2<E<2? >6B6<2D2>A2<A252&2'&6

=6<DB@?I2?85:8E?2<2?52B:<2G2D7:=2>6?A252D23E?892>A2E52B2 5:=6G2D<2?>6=2=E:>652?=:CDB:<56?82?A@D6?C:2=I2?852A2D5:2DEB ,6D6=29 5:9:DE?8A2?;2?886=@>32?8I2?85:>:=:<:@=696=6<DB@?@B56?I2C2>2 36C2B 56?82? ;2B2< 2D@>2D@> 52=2> <B:CD2= 3292? A252D 6?82? >6?82>2D:CE5EDCE5EDA2?DE=6=6<DB@?C6D6=29>6?86?2:<B:CD2=&:.7743

52?*62*6>6>A6B@=69A@=2A@=25:7B2<C:C6A6BD:A252&2'&6I2?8

C2>256?82?A@=25:7B2<C:@=69C:?2B1 "2C:=6<CA6B:>6?&:.774352?

*62*6>6?E?;E<<2?329G2A2BD:<6=C6A6BD:6=6<DB@?52A2D36BC:72DC63282: 86=@>32?8

*2526<CA6B:>6?&:.7743*62*636B<2C6=6<DB@?I2?8;2DE9A252 3:52?8 A6>2?DE= <B:CD2= 56?82? CE5ED 52? 3:52?8 A6>2?DE= I2?8 >6>:=:<:C6=2?8;2B2<C636C2B2<2?>6?892>3EB<2?6=6<DB@?56?82? CE5ED92>3EB "E3E?82?;2B2<2?D2B22D@>52?;2B2<2?D2B23:52?8 A6>2?DE=>6>6?E9:A6BC2>22?36B:<ED

4@C

M

2B:&2'&6D6B=:92D329G252? >6>6?E9:9E3E?82?

C69:?882*6BC2>22?M36BE329>6?;25: C:?

M

%6D:<2 6=6<DB@? 5:A6B46A2D 56?82? 3652 A@D6?C:2= F@=D :?D6B76B6?C:>2<C:>E>2<2?D6B;25:A252 L 6?82?>6?88E?2<2?

*67&2&&3??:=2:2<2?5:A6B@=69E?DE<;2B2<2?D2B22D@>?:<6=

?> $:<2 5:32?5:?8<2? 56?82? ?:=2: I2?8 5:A6B@=69 36B52C2B<2?D6@B:)*64,1.*2<2?>6?892C:=<2??:=2:A2?;2?886=@>32?8 I2?8C2>2

6?82?56>:<:2?A6B9:DE?82?A2?;2?886=@>32?8I2?85:=2<E<2?

@=69&:.7743*62*6 >6?EBED A6B4@322? C2>2 56?82? A2?;2?8

86=@>32?8 36B52C2B<2? D6@B:)* 64,1.* &:.7743*62*6 36B92C:= >6?E?;E<<2? 329G2 >2D6B: >6>:=:<: C:72D 86=@>32?8 *6B4@322? A6B4@322?E?DE<>6>3E<D:<2?<636B2522?A2BD:<6=D6BEC36B<6>32?8 ,2=29C2DE4@?D@9?I2252=29A@=2A@=25:7B2<C:I2?8D6B;25:C63282:2<:32D 36B<2C6=6<DB@?I2?85:;2DE9<2?A252<B:CD2=2=E>:?:E> *6?6>E2?C:72D 86=@>32?8A2BD:<6=C6=2?;ED?I2>6=29:B<2?CE2DE<2;:2?32BE52=2>7:C:<2 I2?85:C63ED>6<2?:<286=@>32?8

*252>2C2C6<2B2?8C:72D86=@>32?8I2?85:>:=:<:A2BD:<6=D6=29 32?I2<5:>2?722D<2? ,:72DC:72D3292?5:C6=:5:<:56?82?>6=:92DA@=2 5:7B2<C:6=6<DB@?I2?85:;2DE9<2?A2523292?D6BC63ED ':<B@C<@A6=6<DB@?

berkas elektron

kristal nikel detektor filamen

Gambar 7.13

Skema alat percobaan Davisson-Germer. Berkas elektron dijatuhkan pada kristal tunggal nikel. Interferensi yang terjadi pada sudut diamati pada detektor.

Gambar 7.14

Gambaran mengenai hamburan elektron oleh bidang kristal.

a

d d a

d

a

2

I2?85:8E?2<2?@=69A2B229=:3:@=@8:E?DE<>6?6=:D:;2C25>:<B@C<@A:C >6BEA2<2?4@?D@9A6>2?722D2?C:72D86=@>32?8A2BD:<6= ':<B@C<@A 6=6<DB@?52A2D>6?892C:=<2?A6B36C2B2?I2?8C2?82DD:?88:

c. Prinsip Ketidakpastian Heisenberg

A2<29 ?52 A6B?29 >6>32I2?8<2? 3282:>2?2 42B2 I2?8 5:8E?2<2?A2B27:C:<2G2?E?DE<>6?82>2D:6=6<DB@??52D6=2936=2;2B D6?D2?8676<7@D@=:CDB:<52?676<@>AD@?A252>2D6B:C636=E>?I2 *252 A6>3292C2?D6BC63EDD6B;25:DE>3E<2?2?D2B27@D@?52?6=6<DB@? *6B:CD:G2 :?:=29I2?85:8E?2<2?@=69A2B27:C:<2G2?E?DE<>6?82>2D:6=6<DB@? @D@?5:D6>32<<2?<62B296=6<DB@?C69:?882D6B;25:DE>3E<2?2?D2B2 <65E2?I2<6>E5:2?7@D@?I2?8D6BA2?DE=<2?@=696=6<DB@?:?:5:2>2D: @=69 A6?82>2D @D@? :?: >6>32G2 :?7@B>2C: D6?D2?8 <636B2522? 6=6<DB@? <2?D6D2A:<636B2522?6=6<DB@?I2?85::?7@B>2C:<2?@=69 7@D@? D6BC63ED 3E<2? <636B2522? 7@D@? I2?8 C636?2B?I2 >6=2:?<2? <636B2522?6=6<DB@?C6D6=29DE>3E<2?56?82?7@D@? 6?82?<2D2=2:? 252<6D:52<A2CD:2?A@C:C:6=6<DB@?2<:32DDE>3E<2?56?82?7@D@? *B:?C:A :?:A6BD2>2<2=:5:<6>E<2<2?@=69*.7*3'*6,52?AB:?C:A:?:5:<6?2= 56?82??2>2AB:?C:A<6D:52<A2CD:2?"6:C6?36B8 .?DE<=63:9;6=2C?I2 A6B92D:<2?82>32B36B:<ED

*252A6B:CD:G2D6BC63ED7@D@?>6>:=:<:>@>6?DE>C636C2B !52? ;:<27@D@?36BDE>3E<2?56?82?6=6<DB@?>@>6?DE>2G2=6=6<DB@?2<2? 36BE329 *6BE3292?I2?8D6A2DD:52<3:C25:B2>2=<2?D6D2A:A6BE3292? :?:C632?5:?856?82?A6BE3292?>@>6?DE>7@D@? ! $25:A6?8E<EB2? D6BC63EDD6=29>6?I6323<2?<6D:52<A2CD:2?C636C2B ) !

)=69<2B6?2<6D:52<A2CD:2?A6?8E<EB2?A@C:C:6=6<DB@?C6<EB2?8 <EB2?8?I2 C2>2 56?82? A2?;2?8 86=@>32?8 I2?8 5:8E?2<2? I2:DE

0 %6D:52<A2CD:2?>@>6?DE>52?A@C:C:?I2252=29

) 0 !

M

$25:5:52=2>D6@B:+6=2D:F:CD:<A@C:C:52?>@>6?DE>CE2DEA2BD:<6= D:52<52A2D5:D6?DE<2?D6A2DC642B236BC2>22? ,6>2<:?36C2B<6D6A2D2? A@C:C:A2BD:<6=C6>2<:?36C2B<6D:52<A2CD:2?>@>6?DE>?I2 ,632=:<?I2 C6>2<:?36C2B<6D6A2D2?92B82>@>6?DE>?I2C6>2<:?<64:=<6D6A2D2? A@C:C:?I2 6B365256?82?D6@B:<=2C:<A@C:C:52?>@>6?DE>CE2DEA2BD:<6= 52A2D5:D6?DE<2?C642B2D6A2D52?36BC2>22?

Gambar 7.15

Tumbukan foton dan elektron ketika mengamati elektron.

Kata Kunci

• gelombang partikel • efek fotolistrik • foton • fungsi kerja • efek Compton

• panjang gelombang de Broglie • jarak antara bidang

• prinsip ketidakpastian Heisenberg

pengamat

momentum elektron semula foton datang

momentum elektron akhir

pengamat pengamat

2 3 4

elektron bertumbukan

&@82>46C:E>>6>:=:<:7E?8C:<6B;26/

2 6B2A2A2?;2?84292I286=@>32?8D6BA2?;2?8 I2?852A2D5:;2DE9<2?A252A6B>E<22?=@82> 46C:E> D2?A2 >6?86=E2B<2? 6=6<DB@? 52B: A6B>E<22?=@82>

3 $:<2 A6B>E<22? =@82> 5:C:?2B: @=69 4292I2 >@?@<B@>2D:<56?82?A2?;2?886=@>32?8?> 9:DE?8=296?6B8:<:?6D:<>2<C:>E>6=6<DB@?7@D@ I2?8<6=E2B52B:A6B>E<22?=@82>

4 6B2A2<29 A@D6?C:2= 96?D: I2?8 >6?292? <6=E2B?I22BEC6=6<DB@?

292I256?82?A2?;2?886=@>32?8?>>6B25:2C: A6B>E<22?=@82>I2?8>6>:=:<:7E?8C:<6B;2PM

;@E=6 $:<2P_>C52?!PM_$C

D6?DE<2?

2 6?6B8:<:?6D:<>2<C:>E>6=6<DB@?7@D@?I2 3 A@D6?C:2=96?D:

,E2DE 36B<2C C:?2B1 56?82? 6?6B8: < 6/ >6?82=2>:92>3EB2?@>AD@?56?82?CE5EDL -6?DE<2?6?6B8:7@D@?C:?2B1C6CE52992>3EB2? *6?E?DE?6?6B8:7@D@?5:BE>EC<2?@=69 ! ,63E297@D@?>6>:=:<:A2?;2?886=@>32?8?>

>6?82=2>:92>3EB2?@>AD@?56?82?CE5EDL

-6?DE<2?=29

2 A2?;2?886=@>32?8

3 6?6B8:7@D@?I2?85:92>3EB<2?

4 6?6B8:I2?85:36B:<2?<6A2526=6<DB@?I2?8 >6=@>A2D

,63E29A2BD:<6=36B86B2<56?82?<646A2D2?P_>C

6B2A2<29A2?;2?886=@>32?8A2BD:<6=;:<2A2BD:<6= D6BC63ED

2 6=6<DB@? 3 AB@D@?

4 3@=236B>2CC2<8

6B2A2<29A2?;2?886=@>32?87@D@?282B>@>6?DE> ?I2C2>256?82?>@>6?DE>6=6<DB@?I2?836B86B2< 56?82?<646A2D2?P_>C

,63ED<2?=298282C2?I2?85:<6>E<2<2?@=6956 B@8=:6

":DE?8=29A2?;2?886=@>32?856B@8=:6I2?85:>:=:<: @=696=6<DB@?I2?836B86B2<56?82?=2;EP_>C

,63E29A2BD:<6=36B>2CC2M_{<8>6>:=:<:A2?;2?8}

86=@>32?856B@8=:6C636C2B?> -6?DE<2?=29 <646A2D2?86B2<A2BD:<6=D6BC63ED

,63E29A2BD:<6=36B86B2<56?82?=2;EP_>C

":DE?8=29 >2CC2 A2BD:<6= D6BC63ED ;:<2 A2?;2?8 86=@>32?856B@8=:6I2?85:>:=:<:A2BD:<6=:DE?>

Tes Kompetensi

Subbab B

*6/&0&31&-5&)&'9091&8.-&3

Rangkuman

+25:2C:6=6<DB@>28?6D:<I2?85:A2?42B<2?@=6936?52 5:C63EDB25:2C:D6B>2=

6?52 9:D2> 252=29 CE2DE C:CD6> I2?8 52A2D >6?I6B2AC6>E2B25:2C:<2=@BI2?8>6?86?2:36?52 2D2EC:CD6>D6BC63ED

'6?EBED,D672?@=DJ>2??:?D6?C:D2CB25:2C:D6B>2= CE2DE36?525:?I2D2<2?56?82?

"E<E>*6B86C6B2?0:6?>6?I2D2<2?329G2A2?;2?8 86=@>32?8 I2?8 CE9E?I2 D:?88: =63:9 A6?56< 52B:A252A2?;2?886=@>32?8:?D6?C:D2C36?52I2?8 CE9E?I2 B6?529 ,642B2 >2D6>2D:C "E<E> *6B86C6B2?0:6?5:?I2D2<2?C63282:36B:<ED

_>2<C<@?CD2?

-6@B:0:6?:?:52A2D>6?6B2?8<2?CA6<DBE>A252 A2?;2?886=@>32?8I2?8A6?56<D6D2A:>6?I:>A2?8 <6D:<2>6?6B2?8<2?A2?;2?886=@>32?8I2?8A2?;2?8 +2I=6:89$62?C >6>A6B@=69 A6BE>EC2? 329G2 :?D6?C:D2CB25:2C:36B32?5:?8D6B32=:<56?82?A2?8<2D 6>A2DA2?;2?886=@>32?8

-6@B:+2I=6:89$62?C:?:52A2D>6?6B2?8<2?CA6<DBE> A252 A2?;2?8 86=@>32?8 I2?8 A2?;2?8 D6D2A: >6?I:>A2?8 <6D:<2 >6?6B2?8<2? A2?;2?8 86=@>32?8I2?8A6?56<

'6?EBED-6@B:*=2?4<6?6B8:B25:2C:I2?85:A2?42B <2?@=6986D2B2?>@=6<E=36?52>6BEA2<2?A2<6D <E2?D26?6B8:I2?836C2B?I2

_?'! ?6B8:E?DE<C2DE7@D@?252=29C636C2B

!

76<7@D@=:CDB:<252=2986;2=2D6B=6A2C?I26=6<DB@? 6=6<DB@?52B:A6B>E<22?A=2D=@82><6D:<25:C:?2B: 56?82?7B6<E6?C:D6BD6?DE *6BC2>22?I2?836B=2<E A25286;2=2:?:252=29

!_$

56?82?!252=297E?8C:<6B;26=6<DB@?A252 =@82>

E?8C:<6B;2252=296?6B8:>:?:>E>I2?85:3EDE9<2? 6=6<DB@?282BD6B=6A2C52B::<2D2?:?D:2D@>A252=@82> 76<@>AD@?>6?;6=2C<2?329G2<6D:<27@D@? >6?E>3E<6=6<DB@?7@D@?>6>36B:<2?6?6B8:A252 6=6<DB@? %69:=2?82?6?6B8:A2527@D@?5:D2?52: 56?82?>6?864:=?I27B6<E6?C:7@D@?2D2E36BD2>329 A2?;2?8?I2A2?;2?886=@>32?87@D@? '@>6?DE> I2?85:>:=:<:7@D@?252=29

!

6?82?>6?88E?2<2?"E<E>%6<6<2=2??6B8: 52?"E<E>%6<6<2=2?'@>6?DE>52=2>5:?2>:<2 B6=2D:F:CD:< 5:52A2D<2? A6BC2>22? 92>3EB2? @>AD@?C63282:36B:<ED

! ! ) & /

,:72D86=@>32?8A252A2BD:<6=A6BD2>2<2=:5:<6?2=<2? @=69&@E:C56B@8=:6 '6?EBED5:2A2?;2?886=@>32?8 A2BD:<6=A2?;2?886=@>32?856B@8=:6252=29

C:?

*B:?C:A<6D:52<A2CD:2?6=6<DB@?>6?882>32B<2? 329G2:?7@B>2C:D6?D2?86=6<DB@?<636B2522??I2 D:52<A2CD: 6C2B?I2<6D:52<A2CD:2?C636C2B

!

)

)=69<2B6?2<6D:52<A2CD:2?A6?8E<EB2?6=6<DB@? C6<EB2?8<EB2?8?I2C2>256?82?A2?;2?886=@>32?8 I2?8 5:8E?2<2? I2:DE 0 ! %6D:52<A2CD:2? >@>6?DE>52?A@C:C:?I2252=29

!2D2E

0 ) 0 !

Peta Konsep

&).&7.*3)&.8&2

D6B;25:A6?I:>A2?82?E?DE< A6?6B2A2??I2

>E?4E=

4@?D@9 A6?6B2A2?I2 >6>3292C

*6BE>EC2?+2I=6:89$62?C

D6B;25:A6?I:>A2?82?E?DE<

2D2E

2D2E

":A@D6C:C*=2?4< '6?8E<EB,E9E

'2D292B:2D2E:?D2?8

>6>3292C

>6>3292C >6>3292C

*2?;2?8!6=@>32?8

56B@8=:6 76< @D@=:CDB:< 76<@>AD@? *B:?C:A

%6D:52<A2CD:2?"6:C6?36B8

E2=:C>6!6=@>32?8*2BD:<6=

#?D6?C:D2C+25:2C: "E<E>*6B86C6B2?0:6?

,:72D!6=@>32?8A252*2BD:<6= ,:72D*2BD:<6=A252!6=@>32?8

Setelah mempelajari materi pada bab ini, Anda tentu dapat memahami mengenai benda hitam. Anda juga paham bahwa cahaya juga dapat bersifat seperti partikel dan partikel bisa bersifat seperti gelombang. Dari keseluruhan materi yang ada pada bab ini, bagian

Refleksi

*252A6B:CD:G2676<7@D@=:CDB:<C6>2<:?36C2B:?D6?C:D2C 4292I2A6?I:?2B2??I2>2<2

2 C6>2<:?36C2B6?6B8:<:?6D:<6=6<DB@?I2?8D6B=6A2C 3 C6>2<:?36C2B<646A2D2?6=6<DB@?I2?8D6B=6A2C 4 C6>2<:?32?I2<6=6<DB@?I2?8D6B=6A2C

5 <646A2D2?52?;E>=296=6<DB@?I2?8D6B=6A2C C2>236C2B

6 6?6B8:I2?8D6BC6B2A@=693292?C6>2<:?36C2B ?6B8: 7@D@? CE2DE 86=@>32?8 6=6<DB@>28?6D:<

36B82?DE?8A252

2 <646A2D2??I2 5 A2?;2?886=@>32?8?I2 3 :?D6?C:D2C?I2 6 CE9E?I2

4 2>A=:DE5@?I2

6B:<ED:?:I2?87@D@??I2>6>:=:<:6?6B8:D6B36C2B 252=29

2 C:?2B>6B29 5 C:?2B1

3 C:?2BE?8E 6 86=@>32?8B25:@ 4 C:?2B82>>2

6C2B?I2A2?;2?886=@>32?856B@8=:652B:C63E29 6=6<DB@?I2?836B86B2<56?82?<6=2;E2?56?82? P_{>C52?>2CC26=6<DB@?P}M_<8

252=29

2 K 5 K

3 K 6 K

4 K

292I2 E=DB2F:@=6D I2?8 5:A6B8E?2<2? E?DE< >6?I:?2B: A6B>E<22? =@82> >6>:=:<: A2?;2?8 86=@>32?8 K =6<DB@?I2?8D6B=6A2C52B: A6B>E<22?=@82>>6>:=:<:6?6B8:<:?6D:<C636C2B 6/ E?8C:<6B;252B:=@82>D6BC63ED252=29

2 6/ 5 6/

3 6/ 6 6/

4 6/

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2 _& 5 _&

3 _& 6 _&

4 _&

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3E296?6B8:C2DE7@D@??I2252=29 2 PM_{$ 5 P}M_$

3 PM_{$ 6 P}M_$

4 PM_$

#"

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2 !/ 5 !/

3 !/ 6 !/2 4 2!/

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2 PM_$

3 PM_$

4 PM_$

5 PM_$

6 PM_$

'8&3&7 *2?;2?886=@>32?8CE2DE7@D@?P_K>6?86?2:

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36C2B6?6B8:<:?6D:<7@D@6=6<DB@?252=29 2 PM_;@E=6

3 PM_;@E=6

4 PM_;@E=6

5 PM_;@E=6

6 PM_;@E=6

'8&3&7 $:<2C:?2BE?8E>6>:=:<:7B6<E6?C:_"J5:;2DE9<2?

A252A6B>E<22?=@82>I2?8>6>:=:<:6?6B8:2>32?8

<2=:<E2?DE>6?6B8:C:?2BE?8E52?D6D2A2?*=2?4< PM_{;@E=6C6<@?6?6B8:<:?6D:<6=6<DB@?I2?8}

5:=6A2C252=29 2 PM_;@E=6

3 PM_;@E=6

4 PM_;@E=6

5 PM_;@E=6

6 PM_;@E=6

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A@D6?C:2=A6?896?D:52=2>F@=D328:?2DB:E>C22D 5:C:?2B:56?82?4292I2I2?87B6<E6?C:?I2P_"J

252=29

2 / 5 /

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4 /

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2 / 5 /

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Tes Kompetensi

Bab 7

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2 >6?8EB2?8::?D6?C:D2CC:?2B?I2 3 >6?2>329:?D6?C:D2CC:?2B?I2 4 >6?2:<<2?7B6<E6?C:C:?2B 5 >6?EBE?<2?7B6<E6?C:C:?2B 6 >6?882?D:=@82>I2?85:C:?2B:

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AB@C6C7@D@=:CDB:<252=29

2 5

3 6

4

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86=@>32?856B@8=:6CE2DE6=6<DB@?I2?836B86B2< 56?82?<6=2;E2? P_>C252=29

2 PM_K

3 PM_K

4 PM_K

5 K 6 K

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3 M_<8>C

4 M_<8>C

5 _<8>C

6 _<8>C

'8&3&7

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2 P_{"J 5 P"J}

3 P_{"J 6 P"J}

4 P_"J

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(:=2:A2528B27:<D6BC63ED252=29 2 PM_{$ 5 P}M_$

3 PM_{$ 6 P}M_$

4 PM_$

#" "E3E?82?6?6B8:<:?6D:<6=6<DB@?52?7B6<E6?C: A6?I:?2B2?A25286;2=27@D@=:CDB:<D6B=:92DA2528B27:< C6A6BD:82>32B

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f_A f _B

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f (Hz)

I

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?6B8:<:?6D:<6=6<DB@?I2?8D6B=6A2C52B:A6B>E<22? =@82>C636C2B6/ A23:=24292I2A6?I:?2B2?52B: =E2BI2?85:A6B8E?2<2?>6>:=:<:7B6<E6?C:_"J

36B2A2<297B6<E6?C:A6?I:?2B2?I2?85:A6B=E<2? CEA2I26?6B8:<:?6D:<6=6<DB@?>6?;25:6/ @D@?52B:86=@>32?86=6<DB@>28?6D:<56?82?A2?;2?8

86=@>32?8K>6?E>3E<C63E296=6<DB@?52=2> BE2?892>A2 ,6D6=29DE>3E<2?7@D@?D6BA2?DE= 56?82?2B29LD6B9252A2B29C6>E=2D6?DE<2?=29 2 A2?;2?886=@>32?87@D@?C6D6=2936BDE>3E<2? 3 6?6B8:7@D@?C6D6=2936BDE>3E<2?

*252C63E29>:<B@C<@A6=6<DB@?6=6<DB@?5:=6G2D<2? A252>652?=:CDB:<56?82?3652A@D6?C:2=6/ $:<2 5:<6D29E:>2CC26=6<DB@?PM_<852?>E2D2?

6=6<DB@?PM_{4@E=@>3D6?DE<2?=29}

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*252C22D7@D@?>6?E>3E<C63E296=6<DB@?7@D@? D6BC63ED36B32=:<2B2952B:2B29?I2C6>E=2 A23:=2 A2?;2?8 86=@>32?8 7@D@? >E=2>E=2 K D6?DE<2?=29

2 A2?;2?886=@>32?8?I2C6D6=2936BDE>3E<2? 3 6?6B8:7@D@?I2?89:=2?8A252C22D36BDE>3E<2? -6?DE<2?=2936C2B?I26?6B8:A6B56D:<I2?85:A2?42B <2?@=69C63E293@=22A:36BA:;2B56?82?5:2>6D6B4>

52? CE9E A6B>E<22? 3@=2 2A: D6BC63ED % :<6D29E:<@67:C:6?6>:C:F:D2C?I2

E?8C:<6B;2C63E29=@82>?2DB:E>252=296/ -6?DE<2?A2?;2?886=@>32?8>2<C:>E>4292I2I2?8 52A2D>6?I6323<2?D6B;25:?I2676<7@D@6=6<DB@? *252CE2DEA6B:CD:G27@D@=:CDB:<6=6<DB@?D6B=6A2C52B:

A6B>E<22?=@82>56?82?<6=2;E2?/A252C22D7B6<E6?C: C:?2B I2?8 5:A2<2: >6?I:?2B: =@82> D6BC63ED -6?DE<2?=29<6=2;E2?6=6<DB@?I2?8<6=E2B52B:A6B >E<22?=@82>;:<27B6<E6?C:C:?2B=E2B5:;25:<2? ,63E297@D@?56?82?A2?;2?886=@>32?8(>

>6?2>3296=6<DB@?5:2> @D@?5:92>3EB<2?56?82? CE5EDC:>A2?82?L52B:2B29C6>E=2 -6?DE<2? A2?;2?886=@>32?87@D@?C6D6=29DE>3E<2?

*2BD:<6=52A2D36BC:72DC63282:86=@>32?856?82? C6?5:B:?I26=6<DB@?2<2?52A2D>6?E?;E<<2?C:72DC:72D :?D6B76B6?C:2D2E5:7B2<C:;:<25:=6G2D<2?A252CE2DE <:C: E<D:<2?329G26=6<DB@?52A2D>6?E?;E<<2? C:72DC:72D D6BC63ED C63282:>2?2 92=?I2 CE2DE 86=@>32?8

A23:=27E?8C:<6B;2CE2DE=@82>252=296/ 36B2A2<29 A2?;2?8 86=@>32?8 A6?I:?2B2? I2?8 5:A6B=E<2?@=69=@82>D6BC63EDCEA2I26?6B8:<:?6D:< 6=6<DB@?I2?852A2D5:=6A2C<2?52B:A6B>E<22?=@82> D6BC63EDC636C2B6/

&;&'1&-5*68&3=&&3'*6.098)*3,&38*5&8

A23:=2<@?CD2?D2*=2?4<!36C2B?I27E?8C:<6B;2 =@82>252=29

2 ! 5 !

3 ! 6 !

4 !

#" ,63E296=6<DB@?I2?85:A6B<64:=A2523652A@D6?C:2= </A252D23E?892>A2E52B22<2?>6?:>3E=<2? A2?;2?886=@>32?8>:?:>E>C636C2B

2 PM_{> 5 P}M_>

3 PM_{> 6 P}M_>

4 PM_>

#" $:<252B:<62522?5:2>?I26=6<DB@?A6BD2>25:A6B46A2D @=6936?52A@D6?C:2=52?6=6<DB@?=2:?56?82?3652

A@D6?C:2=A6B32?5:?82?A2?;2?886=@>32?856

B@8=:66=6<DB@?6=6<DB@?D6BC63EDE?DE<3652A@D6?C:2= 36B@B56</252=29

2

5

3

6

4

$:<252B:<62522?5:2>6=6<DB@?5:A6B46A2D36BDEBED DEBED@=693652A@D6?C:2=F@=D52?

F@=DA6B32?5:?82?A2?;2?886=@>32?856B@8=:6?I2 252=29

2 5

3 6

4

#" 2B:8B27:<36B:<ED9E3E?82?2?D2B2:?D6?C:D2C6?6B8: I2?85:A2?42B<2?@=69A6B>E<22?36?52D6B9252A A2?;2?886=@>32?8_{I2?85:A2?42B<2?252=29}

2 52?

3 52?

4 52?

5 52?

6 52? T_A

T_B I