Halaman
Gelombang Bunyi49Gelombang Bunyi•mendeskripsikan gejala dan ciri-ciri gelombang bunyi;•menerapkan konsep dan prinsip gelombang bunyi dalam teknologi.Setelah mempelajari bab ini, Anda harus mampu: 2A2D<29?52>6>32H2?8<2?5E?:2D2?A2252?H23E?H: E?:22<2?D6B2C2CE?H:D2?A2252?H23E?H:6B282>;6?:C3E?H:>6?;25:<2?5E?:2:?:=63:9O9:5EAP?5252A2D>6?56?82B<2?>EC:<<2B6?2252?H2A6B2>32D2?86=@>32?83E?H:H2?8C2>A2:<6D6=:?82?52+29E<29?52C:72DC:72D52?<=2C:7:<2C:86=@>32?83E?H:,=DB2C@?:<>6BEA2<2?C2=29C2DE;6?:C3E?H:H2?852A2D5:A2?42B<2?@=69<6=6=2G2B 6=@>32?83E?H:D6BC63ED36BA6B2?C63282:OA6?8:?5B2P<6D:<2<6=6=2G2BD6B32?8A252>2=2>92B:*6=2:?E=DB2C@?:<D6B52A2D;6?:C86=@>32?83E?H:=2:??H2,?DE<>6?86D29E:=63:9=2?;EDD6?D2?8;6?:C;6?:C86=@>32?83E?H:C:72DC:72D86=@>32?83E?H:52?76?@>6?276?@>6?2=2:??H2H2?836B<2:D2?56?82?86=@>32?83E?H:C6BD2A6?6B2A2??H252=2>D6<?@=@8:A6=2;2B:=29>2D6B:A252323:?:C642B232:<menerapkan konsep dan prinsip gejala gelombang dalam menyelesaikanmasalah.Hasil yang harus Anda capai:49A. Sifat DasarGelombang BunyiB. Cepat Rambat BunyiC. Unsur Bunyi danPemanfaatanGelombang BunyiD. Sifat-SifatGelombang BunyiE. Dawai dan PipaOrgana sebagaiSumber BunyiF. Energi GelombangBunyiKelelawar ladam kuda (horseshoe bat) dapat memancarkan gelombang bunyiultrasonik yang berfungsi sebagai pengindra ketika terbang pada malam hari.Bab3Sumber:Fundamental of Physics, 2001
Mudah dan Aktif Belajar Fisika untuk Kelas XII50A. Sifat Dasar Gelombang BunyiA2<29?52>6?86D29E:AB@C6CD6B;25:?H23E?H:(25252C2B?H2C6CE2DEH2?836B86D2B252=29CE>36B3E?H:E?H:C66<@B?H2>E<D6B56?82B<2B6?2<6A2<2?3E=E3E=E<65E2C2H2A?H2H2?8>6>:=:<:7B6<E6?C:C6<:D2B
IE?H:C66<@B;2?8<B:<D6B56?82B2<:32D252?H286D2B2?<65E2C2H2A?H2H2?836B86C6<2?C642B2D6BEC>6?6BEC 6=@>32?8:?7B2C@?:<5:A2?42B<2?@=69C66<@BA2EC56?82?7B6<E6?C:C2?82DB6?5295:32G29
ID6D2A:>2>AE5:D2?8<2A@=69A2ECH2?8=2:?G2=2EAE?;2?8<2E2??H2B2DEC2?<:=@>6D6B6B365256?82?CE>36BCE>36B3E?H:D6BC63ED3E?H:A2522=2D2=2D>EC:<H2?852A2D<:D256?82BD6B>2CE<86=@>32?82E5:@C@?:<E?H:H2?8<6=E2B52B:2=2D>EC:<36BC:72DD6B2DEBC69:?8825:?2>2<2?56?82??25252AE?3E?H:H2?8D:52<D6B2DEB5:?2>2<2?56C29(6B92D:<2?#/$#3 (25282>32BD6BC63EDD6B=:92D86D2B2?=@?46?8>6?892C:=<2?86=@>32?83E?H:H2?8>6B2>32D>6=2=E:>65:2E52B2>6?E;ED6=:?82H2?836BEA286=@>32?8=@?8:DE5:?2=(25252C2B?H286=@>32?83E?H:52A2D>6B2>32D5:>65:E>2A2AE?(6B92D:<2? #$'. <6>2>AE2?>65:E>E?DE<>6?886D2B<2?A2BD:<6=36B36523652329<2?252>65:E>H2?852A2D>6B652>3E?H:>:C2=?H22:B 6=@>32?83E?H:52A2D>6?E?;E<<2?C:72DC:72DE>E>86=@>32?8C6A6BD:52A2D>6?82=2>::?D6B76B6?C:5:7B2<C:B67B2<C:52?B6C@?2?C:?52;E822<2?>6>A6=2;2B:A6B:CD:G2CEA6BA@C:C:C6A6BD:CEA6BA@C:C:5E286=@>32?83E?H:H2?8<64:=A6B36522?7B6<E6?C:?H2C69:?882>6?892C:=<2?3E?H:<E2D=6>29C642B2A6B:@5:<H2?85:C63EDA6=2H2?82?3E?H:6B52C2B<2?2B29B2>32D?H2D6B>2CE<86=@>32?82A2<293E?H::DE82B?52>6>292>:?H2A6B92D:<2?#/$#3
#/$#3
>6?E?;E<<2?CE>36B3E?H:36BEA286D2B2?>6>3B2?32C5BE> 6D2B2?C6=2AEDH2?8>6BEA2<2?56?HED36B5:>6?C:5E25:A2?DE=<2?C642B236BE=2?8E=2?8@=6932D2CC6=2AEDC69:?882C6=2AED2<2?36B86D2BC642B2A6B:@5:<#6D:<2C6=2AED36B86B2<<6=E2B2<2?D6B;25:A6>2>A2D2?E52B25:56A2??H2(6>2>A2D2?D6BC63ED>6?H6323<2?D6<2?2?E52B236BD2>329H2?85:C63ED526B29B2A2D2?)2A2D2?36B86B2<>6?;2E9:C6=2AED52=2>32D2C<646A2D2?3E?H:)2A2D2?52?B6?882?82?H2?8D6B36?DE<52B:A2BD:<6=A2BD:<6=E52B2>:B:A56?82?B2A2D2?52?B6?882?82?86=@>32?8=@?8:DE5:?2=A252C=:?<:"25:86=@>32?8=@?8:DE5:?2=>6BEA2<2?C:72D52C2B86=@>32?83E?H: #$'. 6A2D)2>32DE?H:636B2A2292?A252*E9E
L #/##*#0'&+6/'2#5 #/$#5608+/4:B:B=2ED=E>:?:E>6C:52?2;2 6=2C 6=:E> :5B@86?#2HE<6B2C,52B2
Gambar 3.1Gelombang bunyi darilonceng yang bergetarmerambat melalui mediaudara sampai ke telinga.Gambar 3.2Getaran dari membran basdrum membuat partikel udaramerapat dan merenggang. '$'.6//'/2'.#,#3+-104'2'.1/$#0)608+-'3,#-#0.#*41#.41#.$'3+-65&#.#/$6-6.#5+*#0Tes Kompetensi Awal 6B52C2B<2?CE>36B?H23E?H:D6B>2CE<;6?:C86=@>32?82A2 A2<2986=@>32?83E?H:52A2D>6?82=2>:A@=2B:C2C:
A2H2?85:>2<CE556?82?2E5:@C@?:<:?7B2C@?:<52?E=DB2C@?:< A2H2?85:>2<CE556?82?86>252?82E?8 A2<2986=@>32?8H2?85:A2?42B<2?A6>2?42BB25:@D6B>2CE<86=@>32?8=@?8:DE5:?2=rapatanrengganganxtekananudaraSumber:Physics, 1995
Gelombang Bunyi51E?H:52A2DD6B56?82B;:<286D2B2?52B:CE>36B?H252A2D>6B2>32D9:?882<6D6=:?82%65:2B2>32D2??H252A2D36BEA2I2DA252DI2D42:B52?I2D82C"25:5:A6B=E<2?>65:E>E?DE<>6?;2=2B<2?3E?H:%2C:9:?82D<29?52A6B:CD:G2D6?D2?83E?H:H2?852A2D>6B2>32D>6=2=E:C6ED2C36?2?832C29H2?8<65E2E;E?8?H2D6B9E3E?8<2=6?8CECE56?82?32?DE2?CE2B2D6>2??52&29>6?EBED?5252A2D<293E?H:>6B2>32D5:52=2>F2<E>,?DE<>6?86D29E:;2G232??H2=2<E<2?=292<D:F:D2C36B:<EDAktivitas Fisika 3.1Kata Kunci• gelombang bunyi• gelombang longitudinal• gelombang infrasonik• gelombang audiosonik•nada• desah• pelayangan bunyi• ruang vakumGelombang longitudinal adalahgelombang yang arah getarnyasearah dengan arah rambatannyaIngatlah A2<29H2?85:>2<CE556?82?CE>36B3E?H: *63ED<2?C:72DC:72DH2?85:>:=:<:86=@>32?83E?H:
A2<293E?H:52A2D>6B2>32D5:BE2?892>A2E52B2%6?82A2 6B52C2B<2?2B2986D2B?H2D6B>2CE<86=@>32?82A2<293E?H::DE A2<29A6B36522?2?D2B2?25252?56C29Tes Kompetensi Subbab A'3,#-#0.#*&#.#/$6-6.#5+*#0B. Cepat Rambat Bunyi6A2DB2>32D3E?H:D:52<36B82?DE?8A252D6<2?2?E52B2"25:;:<2D6B;25:A6BE3292?D6<2?2?E52B246A2DB2>32D3E?H:D:52<36BE3296A2DB2>32D3E?H:36B82?DE?8A252CE9E*6>2<:?D:?88:CE9EE52B2C6>2<:?36C2B46A2DA6B2>32D2?3E?H: :526B29A68E?E?82?46A2DB2>32D3E?H:=63:9=2>32D52B:A25246A2DB2>32D3E?H:5:<2G2C2?A2?D2: :E52B246A2DB2>32D3E?H:36B82?DE?8A252;6?:CA2BD:<6=H2?8>6>36?DE<E52B2D6BC63ED(6BC2>22??H252A2D5:DE=:C<2?C63282:36B:<ED$
N A2H2?852A2D?52C:>AE=<2?52B:2<D:F:D2CD6BC63ED%6?82A2<6D:<2E52B25:52=2>D23E?85::C2A=2>2<6=2>22?3E?H:;2>G6<6BD6BC63EDD:52<D6B56?82B 2=D6BC63ED>6>3E<D:<2?329G286=@>32?83E?H:>6>6B=E<2?>65:E>E?DE<>6B2>32DTugas Anda 3.1Apakah bunyi termasuk gelombangelektromagnetik? Sebutkan alasan-alasan yang mendasari jawaban Andatersebut.Bunyi dalam Ruang VakumTujuan PercobaanMenyelidiki apakah bunyi dapat merambat melaluiruang hampa.Alat-Alat Percobaan1.Jam weker2.Tabung hampa udara (vakum)Langkah-Langkah Percobaan1.Bunyikan jam weker tanpa ditutup oleh tabungvakum.2.Tutup jam weker dengan tabung vakum. Amatiyang terdengar dari jam weker tersebut.3.Gunakan sebuah pengisap untuk mengisap udaradalam tabung vakum secara perlahan-lahan.4.Amati perubahan intensitas bunyi jam weker tersebut.
Mudah dan Aktif Belajar Fisika untuk Kelas XII522?5:?8<2?<646A2D2?3E?H:52=2>2=E>:?:E>52?2:B;:<2>@5E=EC.@E?8E?DE<2=E>:?:E>
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> C > 4#646A2D2?3E?H:5:2:BD6B?H2D2=63:9<64:=52B:A252<646A2D2?3E?H:52=2>2=E>:?:E> 2=D6BC63ED5:C6323<2?42:B2?=63:9<@>AB6C:36==63:9>E52936BE32936?DE<5:32?5:?8<2?56?82?I2DA252D>@5E=ECE=<42:B2?=63:9<64:=5:32?5:?8<2?56?82?>@5E=EC.@E?8E?DE<I2DA252DContoh 3.1Cepat rambat bunyi di udarabergantung pada suhu udara.IngatlahTugas Anda 3.2Bandingkan nilai cepat rambat bunyidi udara yang Anda dapatkan daripercobaan dan dari buku referensi.Jika ada perbedaan, berikan analisisAnda mengenai hal tersebut.Iskandar mendengarkan kembalisuaranya sebagai gema dari sebuahtebing setelah waktu 4 detik. Jikaadalah perbandingan panas jenisudara pada tekanan dan suhukonstan, serta Iskandar mengetahuibahwa suhu saat itu T kelvin danmassa molekul relatif udara M,Iskandar dapat menentukan jaraktebing menurut persamaan ....a.RTMd. 6RTMb.2RTMe. 8RTMc.4RTMUMPTN 1996Pembahasan:d = 2vtv = RTMd = 2RTtM = 42RTMPembahasan Soal6A2DB2>32D86=@>32?83E?H:5:E52B2A252CE9E
L252=29
> C":<2CE9EE52B2?2:<>6?;25:
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" >@=#CE9E>ED=2<82C<6=F:?>2CC2>@=6<E=82C8B2> >@=6A2DB2>32D3E?H:52=2>I2DA252D5:D6?DE<2?@=69>@5E=EC.@E?852?>2CC2;6?:CI2DD6BC63ED(6BC2>22??H252A2D5:DE=:C<2?C63282:36B:<ED$
N #6D6B2?82?>@5E=EC.@E?8I2DA252D& >>2CC2;6?:CI2DA252D<8 > :52=2>I2D42:B46A2DB2>32D3E?H:5:D6?DE<2?@=69>@5E=ECE=<52?<6B2A2D2?>2CC2;6?:C42:B2?D6BC63ED(6BC2>22??H252A2D5:DE=:C<2?C63282:36B:<ED$
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Gelombang Bunyi53Kata Kunci• cepat rambat bunyi• konstanta Laplace• modulus Young• modulus Bulk$$$$
> C"25:46A2DB2>32D3E?H:36BD2>329>6?;25:
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& > 52?8B2> 4> 6B2A2<2=:=:A2D<29<646A2D2?3E?H:A25232;25:32?5:?8<2?56?82?<646A2D2?3E?H:A2522=E>:?:E>;:<2>@5E=EC.@E?8E?DE<32;252?2=E>:?:E>>2C:?8>2C:?8 Q
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& >C6BD2>2CC2;6?:C32;252?2=E>:?:E>>2C:?8>2C:?88B2> 4>52? 8B2> 4>C. Unsur Bunyi dan Pemanfaatan GelombangBunyi,?CEBE?CEB3E?H:2?D2B2=2:?C63282:36B:<ED1.Tinggi Nada Bunyi(252A@<@<3292C2?C636=E>?H2?52D6=29>6?86D29E:329G23E?H:5:D:>3E=<2?@=69CE2DE36?52H2?836B86D2B*6>2<:?32?H2<;E>=2986D2B2?H2?85:92C:=<2?52=2>C2DEC6=2?8G2<DED6BD6?DE3E?H:H2?85:92C:=<2?2<2?C6>2<:??H2B:?8(25282>32B#/$#3 C6@B2?82?2<D6B=:92DC652?8>6?6>A6=<2?32D2?8=:5:5:;2B:;2B:B@52C6A652H2?8C652?836BAED2B":<2B@52D6BC63ED5:AED2BC6>2<:?46A2D2A2<293E?H:H2?85:92C:=<2?2<2?C6>2<:??H2B:?8+6B?H2D2A252AED2B2?H2?8=2>32D3E?H:H2?8D6B56?82B36B?252B6?529(252C22DAED2B2?B@52C6A6525:A6B46A2D3E?H:H2?8D6B56?82B36B?252D:?88: 2=D6BC63ED>6>3E<D:<2?329G2D:?88:?25236B82?DE?8A2527B6<E6?C:CE>36B3E?H:2.Kuat Bunyi#E2D3E?H:H2?85:92C:=<2?36B82?DE?8A2522>A=:DE5@86D2B2?(6B92D:<2?#/$#3 H2?8>6?6B2?8<2?A6B4@322?A252C6?2B8:D2B(6D:<=29C2=29C2DEC6?2B8:D2B56?82?C:>A2?82?H2?8D:52<D6B=2=E36C2B 6?82B<2?32:<32:<<E2D3E?H:H2?85:92C:=<2?=2=E32?5:?8<2?56?82?<E2D3E?H:H2?85:92C:=<2?@=69C6?2BH2?8C2>2?2>E?56?82?C:>A2?82?H2?8=63:936C2B52B:A252C6>E=2(6D:<2?>2?2<29H2?8>6?892C:=<2?3E?H:=63:9<E2D3.Warna Bunyi-2B?23E?H:>6BEA2<2?3E?H:<92CH2?85:D:>3E=<2?@=69CE2DECE>36B3E?H:E?H:8:D2B36B365256?82?3E?H:3:@=2:DE<2B6?2252G2B?23E?H:(6B36522?D6BC63EDD6B;25:<2B6?2823E?82??2522D2C52??25252C2B52B:CE>36B3E?H:36B36523652G2=2EAE?7B6<E6?C:?H2C2>2Gambar 3.3Lidi dipegang oleh seorang anakdan ditempelkan pada jerujiroda yang berputar.Gambar 3.4Percobaan kuat bunyi yangdihasilkan oleh getaran senar gitardengan (a) simpangan yang kecildan (b) simpangan yang besar.23
Mudah dan Aktif Belajar Fisika untuk Kelas XII544.Batas Pendengaran?52D6?DED6=29>6?86D29E:329G2>2?EC:252?96G2?5:=6?8<2A:56?82?2=2DA6?56?82B2?H2?8C6>AEB?2&2>E?<6>2>AE2?A6?56?82B2??H236B365236522D2C<6>2>AE2?A6?56?82B2?5:E<EB36B52C2B<2?7B6<E6?C:3E?H:%2?EC:2?@B>2=>6>:=:<:32D2CA6?56?82B2?2?D2B2
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96BDI5:C63ED#" ! 636B2A296G2?>2>AE>6?56?82B3E?H:E=DB2C@?:<329<2?96G2?C6A6BD:<6=6=2G2BH2?8>6>:=:<:2=2DA6?8=:92D2?D:52<C632:<2=2DA6?56?82B2??H2>6?88E?2<2?3E?H:E=DB2C@?:<E?DE<>6?86D29E:36?52H2?82525:56A2??H25.Pemanfaatan Gelombang Bunyi 6=@>32?83E?H:32?H2<5:>2?722D<2?52=2><69:5EA2?C692B:92B:>:C2=?H2E?DE<>6?6?DE<2?<652=2>2?=2ED>6?42B:CE>36B>:?H2<52?>6?56D6<C:<6BEC2<2?=@82>,?DE<>6?6?DE<2?<652=2>2?=2ED2=2DA6?56D6<C:H2?85:8E?2<2?5:C63ED! ! # $" *@?2B36<6B;256?82?>6>2?42B<2?86=@>32?8<6>E5:2?A2?DE=2?86=@>32?8D6BC63ED2<2?5:D6B:>2@=69 $ 6?82?>6?86D29E:<646A2D2?86=@>32?8H2?85:E<EB52?G2<DED6>AE986=@>32?8D6BC63ED#652=2>2?=2ED52A2D5:D6?DE<2?56?82?>6?88E?2<2?A6BC2>22?36B:<ED!$ "
N 2<D@BC6D6?8295:56A2?"A252 '34#/##0 9 >6?H2D2<2?C6D6?829G2<DED6>AE952B:C@?2B<6D6>A2DA6>2?DE=2? B6<E6?C:H2?85:8E?2<2?@=69C@?2B36B252A252526B29E=DB2C@?:<H2:DE5:2D2C
96BDI B6<E6?C:D6BC63EDD:52<52A2D5:56?82B52?A2?;2?886=@>32?8A252526B29E=DB2C@?:<C2?82D<64:=C69:?8825:7B2<C:H2?8D6B;25:;E82C6>2<:?<64:=52?86=@>32?8D:52<2<2?>6?H632B#64:=?H2A2?;2?886=@>32?8H2?85:8E?2<2?52A2D;E825:8E?2<2?E?DE<>6?56D6<C:36?5236?52H2?8<64:=(6?88E?22?86=@>32?8E=DB2C@?:<D6B52A2D;E82A2522=2D#" ! ,* =2DD6BC63EDE>E>?H25:8E?2<2?E?DE<>6?82?2=:C:C<692>:=2?2D2E>6?56D6<C:@B82?@B82?52=2>DE3E9Gambar 3.6Teknologi 3D USG terbaru sekarangdapat melihat organ-organ tubuhbayi dalam kandungan.Sumber:www.mediajakartaselatan.comGambar 3.5Sonar dapat digunakan untukmendeteksi kedalaman laut.pemancarpenerima gelombangultrasonikContoh 3.3*63E292=2DC@?2B5:8E?2<2?E?DE<>6?8E<EB<652=2>2?=2ED*6=2?8G2<DEH2?85:42D2D@=69C@?2BE?DE<86=@>32?8A6B2>32D2?C2>A2:<6>32=:=28:<6C@?2B252=29 C6<@?":<246A2DB2>32D86=@>32?85:52=2>2:B=2ED252=29
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>6D6BKata Kunci• tinggi nada• kuat bunyi•audiosonik•infrasonik•ultrasonik• resonansi•sonar•ultrasonografi12345
Gelombang Bunyi55Tes Kompetensi Subbab C'3,#-#0.#*&#.#/$6-6.#5+*#0 ?52>6?56?82B92=:=:?D2B C6<@?C6D6=29<:=2DD6B=:92D":<246A2DB2>32D3E?H:5:E52B2
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%6?82A2<6=6=2G2BH2?8D6B32?8A252>2=2>92B:D:52<A6B?29>6?23B2<36?5236?52H2?82525:56<2D?H2 ":<2D:?88:?2525:?2:<<2?3282:>2?2<29A6BE3292?H2?8D6B;25:A2522 7B6<E6?C:3 A2?;2?886=@>32?84 46A2DB2>32D86=@>32?85 2>A=:DE5@86=@>32?8 ":<2<E2D3E?H:5:?2:<<2?3282:>2?2<29A6BE3292?H2?8D6B;25:A2522 7B6<E6?C:3 A2?;2?886=@>32?84 46A2DB2>32D86=@>32?85 2>A=:DE5@86=@>32?8D. Sifat-Sifat Gelombang Bunyi?52D6=29>6>A6=2;2B:C:72DC:72DE>E>D6?D2?886=@>32?8H2:DEA6>3:2C2?B67B2<C:A6>2?DE=2?B67=6<C:A6=6?DEB2?5:7B2<C::?D6B76B6?C:52?A@=2B:C2C:E?H:>6BEA2<2?C2=29C2DE36?DE<86=@>32?8'=69<2B6?2:DE86=@>32?83E?H:;E82>6?82=2>:A6B:CD:G2A6B:CD:G2D6BC63ED1.Pemantulan Gelombang Bunyi%6?82A2C22D?5236BD6B:2<5:C6<:D2BD63:?8C6=2=E2523E?H:H2?8>6?:BE<2?CE2B2?52D6BC63ED%6?82A2CE2B2?52D6B56?82B=63:9<6B2C<6D:<236B2525:52=2>865E?8#65E2A6B:CD:G2D6BC63ED>6?E?;E<<2?329G23E?H:52A2D5:A2?DE=<2?,?DE<>6>292>:D6?D2?8A6>2?DE=2?3E?H:=2<E<2?=292<D:F:D2C36B:<EDTugas Anda 3.3Gelombang bunyi merupakangelombang longitudinal sehinggatidak dapat mengalami dispersi danpolarisasi. Diskusikanlah bersamateman Anda, mengapa hal tersebutbisa terjadi? Berikanlah penjelasanilmiah mengenai hal tersebut.Aktivitas Fisika 3.2Pemantulan BunyiTujuan percobaanMembuktikan peristiwa pemantulan bunyi.Alat-Alat Percobaan1.Weker4.Dua buah pipa berdiameter 1 inci2.Papan pemantul5.Busur derajat3.Meja6.Kertas karton putihLangkah-Langkah Percobaan1.Susunlah alat seperti tampak pada gambar.2.Letakkan jam weker di salah satu ujung pipa paralon.3.Atur pipa paralon yang lain agar Anda dapat mendengar bunyi jam weker yangpaling jelas.4.Gambarlah susunan pipa tersebut pada kertas karton putih yang Andaletakkan di bawahnya. Ukurlah besar sudut datang dan sudut pantulnya.5.Ulangi langkah percobaan ke-3 dan ke-4 dengan sudut yang berbeda.
Mudah dan Aktif Belajar Fisika untuk Kelas XII5623Gambar 3.8(a) Pada siang hari, arah rambatbunyi melengkung ke atas.(b) Pada malam hari, arah rambatbunyi melengkung ke bawah.Gambar 3.7Proses pemantulan bunyi.$E<:C2?82B:CH2?8?523E2DD6?D2?8CE5ED52D2?8CE5EDA2?DE=52?82B:C?@B>2=A252A6>2?DE=2?3E?H:2<2?C2>256?82?#/$#3 (25282>32BD6BC63EDD6B=:92D329G2CE5ED52D2?8CE5EDA2?DE=52?82B:C?@B>2=D6B=6D2<A252C2DE3:52?852D2B52?%6?82A23E?H:52=2>BE2?82?D6BDEDEAD6B56?82B=63:9<6B2C$6D2<5:?5:?8BE2?82?H2?8D6B=2=E56<2D>6?H6323<2?3E?H:A2?DE=D:52<4E<EAG2<DEE?DE<>6B2>32DC69:?8823E?H:52D2?852?3E?H:A2?DE=D6B56?82BC642B236BC2>22? 2=D6BC63ED>6>3E<D:<2?329G23E?H:A2?DE=52A2D>6>A6B<E2D3E?H:2C=:?H2!DE=29C6323?H2CE2B2>EC:<2<2?D6B56?82B=63:9<6B2C5:52=2>BE2?82?52B:A2525:=2A2?82?D6B3E<26B365256?82?86>2H2?8D6B;25:;:<2?5236BD6B:2<5:526B2936BD63:?8"2B2<D63:?852?CE>36B3E?H:H2?84E<EA;2E9>6?H6323<2?3E?H:A2?DE=>6>6B=E<2?G2<DEH2?84E<EA=2>2E?DE<>6B2>32DC2>A2:A6?56?82B2?<:32D?H23E?H:A2?DE=2<2?D6B56?82BC6D6=293E?H:2C=:636B2A2A6B:CD:G2D6BC63ED>6BEA2<2?A6?82=2>2?H2?8C6B:?8?52D6>E<2?2.Pembiasan Gelombang Bunyi?52 D6=29 >6?86D29E: 86=@>32?8 3E?H:>6B2>32D<6C6>E22B2952?86=@>32?83E?H:D:52<52A2DD6BA@=2B:C2C:%6?82A2A252>2=2>92B:CE2B225I2?2D2ECE2B2D6B:2<2?H2?84E<EA;2E9D6B56?82B=63:9;6=2C52B:A252C:2?892B:(252C:2?892B:CE9EE52B25:A6B>E<22?=63:9D:?88:52B:A2525:2D2C?H2 2=D6BC63ED>6?H6323<2?=2A:C2?E52B2A252328:2?2D2C=63:9B2A2D52B:A2525:32G29?H2*632=:<?H2A252>2=2>92B:=2A:C2?E52B25:A6B>E<22?=63:9B2A2D52B:A2525:2D2C?H2<:32D?H2A252C:2?892B:;:<2CE>36B3E?H:52D2?8C642B29@B:I@?D2=D6B9252AA6?56?82B52A2D5:A2CD:<2?2B29B2>32D3E?H:2<2?>6=6?8<E?8<62D2CC652?8<2?A252>2=2>92B:2B29B2>32D3E?H:2<2?>6=6?8<E?8<632G29(6B92D:<2?#/$#3 A2H2?82<2?D6B;25:;:<23E?H:52D2?8?H2>6B2>32DF6BD:<2=<632G29(252>2=2>92B:2B29B2>32D3E?H:5:3:2C<2?>6?56<2D:82B:C?@B>2=*632=:<?H2A252C:2?892B:2B29B2>32D3E?H:5:3:2C<2?>6?;2E9:82B:C?@B>2=*6CE2:56?82?9E<E>A6>3:2C2?86=@>32?8329G286=@>32?852D2?852B:>65:E><EB2?8B2A2D<6>65:E>=63:9B2A2D2<2?5:3:2C<2?>6?56<2D:82B:C?@B>2=2D2EC632=:<?H23.Difraksi Gelombang BunyiA2<2986=@>32?83E?H:52A2D>6?82=2>:5:7B2<C:2D2EA6=6?DEB2?(6B:CD:G2A6=6?DEB2?3E?H:52A2D5:2>2D:<6D:<2?52>6?56?82B56BE3E?H:>@3:=>6=:?D2C:526B29A6B3E<:D2?H2?836B<6=@<CE2B2A6B42<2A2?D6>2?D6>2??525:BE2?82?H2?836B36522D2E<242A6>32D2C=@<6DA6>32H2B2?5:C63E2932?<H2?8C6?82;25:3E2D56?82?3636B2A2=E32?8<64:=282B86=@>32?83E?H:D:52<>6>2?DE=G2=2EAE?2B29B2>32D3E?H:D:52<36BEA282B:C=EBEC+:82A6B:CD:G2D6BC63ED>6BEA2<2?4@?D@9A6?6B2A2?5:7B2<C:3E?H:"25:2A2<29H2?85:>2<CE556?82?5:7B2<C::DE :7B2<C:252=29A6B:CD:G2A6=6?DEB2?86=@>32?8<6D:<2>6=6G2D:46=29H2?8E<EB2?46=29?H2C6@B5656?82?A2?;2?886=@>32?8?H2ANCriPelayangan bunyi terjadi karenaadanya interferensi dua gelombangyang frekuensinya berbeda sedikit.Ingatlah
Gelombang Bunyi57$2=E>6?82A286=@>32?83E?H:>E529>6?82=2>:5:7B2<C: 6=@>32?83E?H:5:E52B2>6>:=:<:A2?;2?886=@>32?8C6<:D2B3636B2A2C6?D:>6D6BC2>A2:3636B2A2>6D6B2?5:?8<2?56?82?4292H2H2?8>6>:=:<:A2?;2?886=@>32?836B<:C2B
>>!DE=29C6323?H286=@>32?83E?H:=63:9>E529E?DE<D6B5:7B2<C:4.Interferensi Gelombang Bunyi#6D:<2?5236B5:B:5:56A2?5E2 #! A6?86B2CCE2B2C63282:CE>36B3E?H:<6>E5:2?36B;2=2?=EBECC6;2;2B56?82?82B:CA6?89E3E?8<65E2 #! D6BC63ED+2<=2>2C6D6=29:DE?522<2?>6?56?82B3E?H:=6>2952?C6C22D<6>E5:2?D6B56?82B3E?H:<E2DE?H:<E2DD6B;25:<6D:<2CEA6BA@C:C:52B:5E286=@>32?83E?H:>6?892C:=<2?:?D6B76B6?C:56CDBE<D:7!?D6B76B6?C:D6BC63EDD6B;25:;:<23652=:?D2C2??H2>6BEA2<2?<6=:A2D2?3:=2?82?3E=2D52B:C6D6?829A2?;2?886=@>32?83E?H:C642B2>2D6>2D:C5:DE=:C<2?C63282:36B:<ED! 56?82?
52? 36BDEBEDDEBEDE?DE<3E?H:<E2DA6BD2>23E?H:<E2D<65E252?3E?H:<E2D<6D:825.Pelayangan Bunyi!?D6B76B6?C:H2?85:D:>3E=<2?52B:5E286=@>32?83E?H:52A2D>6?H6323<2?A6B:CD:G2A6=2H2?82?3E?H:H2:DEA6?8E2D2?52?A6=6>292?3E?H: 2=D6BC63EDD6B;25:2<:32DCEA6BA@C:C:5E286=@>32?8H2?8>6>:=:<:7B6<E6?C:H2?8C65:<:D36B365252?>6B2>32D52=2>2B29H2?8C2>2"25:C2DEA6=2H2?82?5:567:?:C:<2?C63282:5E23E?H:<6B2C2D2E5E23E?H:=6>29H2?8D6B;25:C642B236BEBED2?=2H2?82?<E2DN=6>29N<E2D2D2E=6>29N<E2DN=6>29":<2<65E286=@>32?83E?H:D6BC63ED>6B2>32D36BC2>22?2<2?>6?892C:=<2?3E?H:A2=:?8<E2DC22D72C6<65E2?H2C2>2":<2<65E286D2B2?36B=2G2?2?72C62<2?5:92C:=<2?3E?H:A2=:?8=6>29%:C2=<2?5E2CE>36B3E?H:>6>:=:<:7B6<E6?C:52?C65:<:D36B3652C:>A2?82?C6D:2A86=@>32?8A252A@C:C:D6BD6?DE252=29&C:? "52?&C:? " 6?82?56>:<:2?CEA6BA@C:C:C:>A2?82?<65E286=@>32?8D6BC63ED252=29C:? C:? && & "" &C:? C:? " "56?82?>6?88E?2<2?2DEB2?C:?EC2<2?5:A6B@=69 4@C C:? & """" 4@C C:? "" ":<2 52?>2<2f52?(6BC2>22?CEA6BA@C:C:52A2D5:DE=:C<2?>6?;25:& 4@C "C:? "AC:? "
NKata Kunci• dispersi• refraksi• refleksi• difraksi• interferensi• polarisasi• superposisisin A + sin B = 2 cos 12 (A–B) sin 12(A+B)Ingatlah
Mudah dan Aktif Belajar Fisika untuk Kelas XII58E. Dawai dan Pipa Organa sebagai Sumber Bunyi1.Frekuensi Gelombang pada Dawai?52D6=29>6>A6=2;2B:329G236?5236?52H2?836B86D2B>6BEA2<2?CE>36B3E?H:D6D2A:D:52<C6>E23E?H:52A2D5:56?82B@=69D6=:?82>2?EC:2 2=D6BC63ED5:C6323<2?D6=:?82>2?EC:2?@B>2=>6>:=:<:7B6<E6?C:2>32?8>:?:>2=H2:DE7B6<E6?C:D6B6?52952B:CE>36B3E?H:H2?8>2C:952A2D5:D6B:>2@=69D6=:?82Tes Kompetensi Subbab D'3,#-#0.#*&#.#/$6-6.#5+*#0 "6=2C<2?A6?86BD:2?5:7B2<C:86=@>32?83E?H: ":<2252D:82CE>36B3E?H:H2?8:56?D:<5:=6D2<<2?>2C:?8>2C:?836B;2B2< >56?82?H2?8=2:??H2<2A2?<29D6B;25::?D6B76B6?C:>2<C:>E>52B:<6D:82CE>36B3E?H:D6BC63ED
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IN I"25:7B6<E6?C:A6=2H2?82??H2252=29N IContoh 3.4 4@C "
N6B52C2B<2? '34#/##0 9:?D6?C:D2C3E?H:2<2?>2<C:>2=;:<2& '=69<2B6?2:DE=2H2?82?3E?H:D6B;25:;:<2 4@C "36B?:=2: 52?N C69:?8827B6<E6?C:=2H2?82??H2252=29fffp()12
N#6D6B2?82? 7B6<E6?C:A6=2H2?82? I7B6<E6?C:86=@>32?8& I7B6<E6?C:86=@>32?8& IDua buah dawai baja yang identikmemberikan nada dasar denganfrekuensi 400 Hz. Bila tegangandalam salah satu dawai ditambah2%, frekuensi pelayangan yangterjadi adalah ....a.0 Hzd.6 Hzb.2 Hze.8 Hzc.4 HzTes ITB 1975Pembahasan:Diketahui:f0 = 400 HzTegangan ditambah 2%p’ = F + 2% F = 1,02 Fmaka01, 0 2’1, 0 1fFFfF F sehingga frekuensi layangannyaadalahfp= (f2 – f1)= (1,01 f0 – f0)= 0,01 f0= 0,01 · 400 Hz= 4 HzJawaban: cPembahasan Soal
Gelombang Bunyi59Gambar 3.9(a) Nada dasar f0;(b) Nada atas pertama f1;(c) Nada atas kedua f2;(d) Nada atas ketiga f3.(@=286D2B2?52G2:A252#/$#3 #>6?892C:=<2??25252C2B56?82?2D2E>2<2$$(@=286D2B2?52G2:A252#/$#3 $>6?892C:=<2??2522D2CA6BD2>256?82?2D2E>2<2$$(@=286D2B2?52G2:A252#/$#3 %>6?892C:=<2??2522D2C<65E256?82?2D2E>2<2$$ $(@=286D2B2?52G2:A252#/$#3 &>6?892C:=<2??2522D2C<6D:8256?82?2D2E>2<2$$ $(6B32?5:?82?7B6<E6?C:?252?252A25252G2:H2?85:92C:=<2?36BEA2A@=286=@>32?8C6A6BD:A252#/$#3 252=29C63282:36B:<ED
N'=69<2B6?246A2DB2>32D86=@>32?8A25252G2:C6CE2:56?82?92C:=2'3%1$##0'.&'H2:DE$ >2<25:A6B@=692 7B6<E6?C:?25252C2B 3 7B6<E6?C:?2522D2CA6BD2>2 4 7B6<E6?C:?2522D2C<65E2 5 7B6<E6?C:?2522D2C<6
N2345012122232*2=29C2DECE>36B3E?H:252=2952G2:8:D2B&252H2?85:92C:=<2?52G2:8:D2B52A2D5:E329E32956?82?42B2>6?6<2?C6?2BA252D:D:<D:D:<D6BD6?DE(@=286=@>32?8H2?852A2DD6B;25:A25252G2:8:D2B5:DE?;E<<2?A252#/$#3 56?82?36BE329E329*2DE52G2:52A2D>6>36?DE<36B3282:7B6<E6?C:2D2EA@=286D2B2?C6A6BD:D2>A2<A252#/$#3 Echolocation adalah bentuk sensoryang digunakan oleh binatangseperti kelelawar, paus, dan lumba-lumba. Binatang tersebutmemancarkan gelombang suara(gelombang longitudinal), kemudiandipantulkan oleh objek. Gelombangpantul kemudian dideteksi olehbinatang tersebut. Gelombangecholocation yang dipancarkan olehkelelawar memiliki frekuensi sekitar175.000 Hz.Echolocation is a form of sensoryperception used by animals such asbats, toothed whales, and porpoises.The animal emits a pulse of sound (alongitudinal wave) which is reflectedfrom objects. The reflected pulse isdetected by the animal. Echolocationwave emitted by bats havefrequencies of about 175.000 Hz.Informasiuntuk AndaInformation for You
Mudah dan Aktif Belajar Fisika untuk Kelas XII602.Pipa Organa dan Pola Gelombangnya+6=29?52<6D29E:329G236?52H2?836B86D2B52A2D>6?892C:=<2?3E?H:+:52<92?H236?52A252DC6A6BD:52G2:D2=:>2EAE?A6=2D=@82>H2?852A2D36B86D2B86D2B2?AE?52A2DD6B;25:A25282C>:C2=?H2E52B2 6D2B2?<@=@>E52B2A252C6BE=:?82<2?>6?892C:=<2?3E?H:+:?88:?252H2?85:A6B@=6952B:C63E29C6BE=:?852A2D5:2DEB7B6<E6?C:?H2 :2?D2B2A6B2?8<2D>EC:<C656B92?2H2?852A2D>6?892C:=<2?86D2B2?<@=@>E52B2C6=2:?C6BE=:?8252=29A:A2@B82?2+6B52A2D5E2>242>A:A2@B82?2H2:DEA:A2@B82?2D6B3E<252?A:A2@B82?2D6BDEDEAa.Pipa Organa Terbuka(:A2@B82?2D6B3E<2252=292=2DD:EA36BEA2D23E?8H2?8<65E2E;E?8A6?2>A2?8?H2D6B3E<2#65E2E;E?8A:A2@B82?2D6B3E<2>6?;25:A6BED86=@>32?8A252<@=@>E52B2(@=286=@>32?8H2?85:92C:=<2?C6A6BD:D2>A2<A252#/$#3 B6<E6?C:H2?85:92C:=<2?@=69A:A2@B82?2D6B3E<2252=29C63282:36B:<ED &25252C2B2D2E B6<E6?C:H2?85:92C:=<2?$$Gambar 3.10Seruling merupakan pipaorgana terbuka.*6ED2C52G2:H2?8<65E2E;E?8?H2D6B:<2D>6>:=:<:A2?;2?8 >>2CC2;6?:C?H2
8 4>>6?892C:=<2?7B6<E6?C:?25252C2B
I2 :DE?8=2982H2D682?82?52G2:3 6B2A2<2936C2B7B6<E6?C:52?A2?;2?886=@>32?8A252?2522D2CA6BD2>24 +6?DE<2?=297B6<E6?C:52?A2?;2?886=@>32?8A25252G2:E?DE<?2522D2C<65E2#7#$ :<6D29E: >
<8 4>
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<8 4>
I
&"25:36C2B82H2D682?82?52G2:252=29
&3 B6<E6?C:?2522D2CA6BD2>2 252=29 2D2E
I
I(2?;2?886=@>32?8A252?2522D2CA6BD2>2252=29 >4 B6<E6?C:A252?2522D2C<65E2 252=29 2D2E
I
I(2?;2?886=@>32?8A252?2522D2C<65E2252=292D2E
>Contoh 3.5(6BC2>22?7B6<E6?C:?252?252D6BC63ED<2=:A6BD2>25:E?8<2A<2?@=69'34'00'C69:?882 '34#/##0 9D6BC63ED5:<6?2=56?82?6-6/'34'00'
Gelombang Bunyi61Gambar 3.11Pola gelombang resonansisuatu pipa organa terbuka.nada dasar atauharmonik pertamanada atas pertama atauharmonik keduanada atas ketiga atauharmonik ketiga012132 &2522D2CA6BD2>22D2E B6<E6?C:H2?85:92C:=<2?$$
&2522D2C<65E22D2E B6<E6?C:H2?85:92C:=<2?$$ &2522D2C<6 ? B6<E6?C:H2?85:92C:=<2? $
N(6B32?5:?82?7B6<E6?C:86=@>32?8H2?85:>:=:<:<@=@>E52B2A252A:A2@B82?2D6B3E<2C2>256?82?A6B32?5:?82?7B6<E6?C:86=@>32?8A25252G2:(6B32?5:?82?7B6<E6?C:H2?85:92C:=<2?@=69C6D:2AA@=286=@>32?8E?DE<A:A2@B82?2D6B3E<2252=29
$$ $
N
'34#/##0 9 H2?8>6BEA2<2?A6B32?5:?82?7B6<E6?C:5:<6?2=C63282:6-6/'3016..+52?>6BEA2<2?A6B32?5:?82?3:=2?82?3:=2?82?3E=2D*63E29A:A2@B82?2D6B3E<2A2?;2?8?H2
4>+6?DE<2??25252C2BH2?85:92C:=<2?A:A2D6BC63ED;:<246A2DB2>32D3E?H:5:E52B2
> C#7#$ :<6D29E:A2?;2?8A:A2
4>
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> C 6?82?>6?88E?2<2? '34#/##0 97B6<E6?C:?25252C2B5:A6B@=692D2E>2<2
>
>Contoh 3.6140 cm2*H2B2DD6B;25:?H2?25252C2BH2:DE
> C I
>$ *63E29A:A2@B82?2D6B3E<2H2?8A2?;2?8?H2 >52?7B6<E6?C:92B>@?:<?H236BDEBEDDEBED
I52?
I+6?DE<2?46A2DB2>32D3E?H:A252A:A2@B82?2D6BC63EDContoh 3.7
Mudah dan Aktif Belajar Fisika untuk Kelas XII62b.Pipa Organa Tertutup(:A2@B82?2D6BDEDEA252=292=2DD:EA36BEA2D23E?8H2?8C2=29C2DEE;E?8A6?2>A2?8?H2D6BDEDEA*2=29C2DEE;E?8A:A2@B82?2D6BDEDEA>6?;25:C:>AE=86=@>32?8A252<@=@>E52B252?E;E?8=2:??H2H2?8D6B3E<2>6?;25:A6BED86=@>32?8(@=286=@>32?8H2?85:92C:=<2?D2>A2<C6A6BD:#/$#3
B6<E6?C:H2?85:92C:=<2?@=69A:A2@B82?2D6BDEDEA252=29C63282:36B:<ED &25252C2B2D2E7B6<E6?C:H2?85:92C:=<2?$$ &2522D2CA6BD2>22D2E7B6<E6?C:H2?85:92C:=<2?
$$
&2522D2C<65E22D2E7B6<E6?C:H2?85:92C:=<2?$$ &2522D2C<6N ? 2D2E B6<E6?C:H2?85:92C:=<2? $
N (6B32?5:?82?7B6<E6?C:H2?85:92C:=<2?@=69C6D:2AA@=286=@>32?8E?DE<A:A2@B82?2D6BDEDEA252=29
$$ $
N '34#/##0 9
H2?8>6BEA2<2?A6B32?5:?82?7B6<E6?C:5:<6?2=C63282:6-6/'3016..+52?>6BEA2<2?A6B32?5:?82?3:=2?82?3:=2?82?82?;:=Gambar 3.12Pola gelombang resonansi padasuatu pipa organa tertutup.harmonik kedua134harmonik ketiga254harmonik pertama014#7#$%:C2=<2??
I52??
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Gelombang Bunyi63*63E29A:A2@B82?2D6BDEDEA>6>:=:<:A2?;2?8 4>A23:=246A2DB2>32D3E?H:C22D:DE
> CD6?DE<2?7B6<E6?C:?25252C2B?2522D2CA6BD2>252??2522D2C<65E2#7#$ :<6D29E: 4>
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IContoh 3.8*63E29A:A2@B82?2D6B3E<2 56?82?A2?;2?8
4>D6B;25:
3E29C:>AE=&252A:A2@B82?2D6BC63ED36B6C@?2?C:56?82?A:A2@B82?2D6BDEDEA 52?>6>36?DE< 3E29C:>AE=6B2A2A2?;2?8A:A2@B82?2H2?8D6BDEDEA#7#$)6C@?2?C:D6B;25:;:<2 C2>256?82?(2?;2?8A:A2@B82?2D6B3E<2
4>D6B;25:
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4>
4>(252A:A2@B82?2D6BDEDEAD6B;25: C:>AE=52? A6BEDC69:?8822D2E>2<2$56?82?>6?88E?2<2?CH2B2DB6C@?2?C:A2?;2?8A:A2@B82?2D6BDEDEA52A2D5:9:DE?8
4>
4>$$ Contoh 3.9Pipa organa terbuka A dan pipaorgana tertutup sebelah B memilikipanjang yang sama. Perbandinganfrekuensi nada atas pertama antarapipa organa A dengan pipa organa Badalah ....a.1 : 1d.3 : 2b.2 : 1e.4 : 3c.2 : 3UMPTN 1995Pembahasan:Pipa organa terbuka:31, , , ....22A Pada nada atas pertama:AAAvvfxPipa organa tertutup:351, , , ....444BPada nada atas pertama:3443BB3443BBBvvvf Untuk AB, diperoleh4334AABBvffvJawaban: ePembahasan Soal3.Resonansi(6B:CD:G2:<ED36B86D2B?H2CE2DE36?52<2B6?225236?52=2:?H2?836B86D2B5:C63ED ! !*H2B2DD6B;25:?H2B6C@?2?C:252=297B6<E6?C:86D2B<65E236?5292BECC2>22D2E7B6<E6?C:36?52H2?8:<ED36B86D2BC2>256?82?<6=:A2D2?3:=2?82?3E=2D52B:7B6<E6?C:36?52H2?836B86D2B(6B92D:<2?5E24@?D@9A6B:CD:G2B6C@?2?C:36B:<ED:?:a.Resonansi pada Garputala":<2C63E2982BAED2=25:AE<E=82BAED2=2D6BC63ED36B86D2BC6A6BD:A252#/$#3 B6<E6?C:86=@>32?83E?H:H2?85:92C:=<2?36B82?DE?8A25236?DE<36C2B52?3292?=@82>82BAED2=2D6BC63ED#6D:<25:56<2D<2?A25282BAED2=2H2?8=2:?52?>6>:=:<:7B6<E6?C:3E?H:C2>282BAED2=2<65E22<2?:<ED36B86D2B(6B:CD:G2:<ED36B86D2B?H282BAED2=2H2?8<65E25:C63EDB6C@?2?C:Gambar 3.13Dua garputala yang memilikifrekuensi yang sama akanberesonansi.
Mudah dan Aktif Belajar Fisika untuk Kelas XII64Aktivitas Fisika 3.3gelasairmineralparalongarputalaselangplastikgabusneonCepat Rambat BunyiTujuan PercobaanMengukur cepat rambat bunyi di udara.Alat-Alat Percobaan1.Garputala2.Lampu neon yang sudah tidak terpakai3.Botol air mineral 100 m4.Selang plastik berdiameter 1,5 cm dan panjang 2 m5.Pipa paralon berdiameter 3 cm dan panjang 1 m6.Penjepit7.Penggaris8.Gabus sebagai sumbatLangkah-Langkah Percobaan1.Rangkailah alat-alat tersebut seperti pada gambar.2.Isilah lampu neon dengan air sampai ketinggiankolom udara 5 cm.3.Getarkanlah garputala di atas lampu neon yangterbuka.4.Lakukan pemompaan terhadap air dari lampu neonagar air keluar melalui selang dengan botol air mineral secara perlahan-lahan.b.Resonansi pada Kolom Udara(6B92D:<2?#/$#3 H2?8>6>A6B=:92D<2?A6B:CD:G2B6C@?2?C:A252<@=@>E52B2":<2<@=@>E52B2H2?8D6B=6D2<5:2D2CA6B>E<22?2:B5:86D2B<2?56?82?>6?88E?2<2?C63E2982BAED2=2>@=6<E=>@=6<E=E52B25:52=2><@=@>E52B22<2?:<ED36B86D2B*H2B2DD6B;25:?H2B6C@?2?C:A252<@=@>E52B2252=29 D6A2DA252A6B>E<22?2:B92BECD6B36?DE<B2A2D2? C:>AE=86=@>32?8 A252E;E?8A6B>E<22?<@=@>E52B2>6BEA2<2?A6BED B6?882?82?86=@>32?8,?DE<>6?52A2D<2?B6C@?2?C:A2?;2?8<@=@>E52B25:2D2CA6B>E<22?92BEC5:E329E32952AE?7B6<E6?C:52?A2?;2?886=@>32?83E?H:?H2D6D2A)6C@?2?C:A6BD2>22<2?D6B;25:;:<2A2?;2?8<@=@>E52B25:2D2CA6B>E<22?2:BB6C@?2?C:<65E2B6C@?2?C:<6D:8252?C6D6BEC?H2*2>292=?H256?82?86D2B2?E52B2A252A:A2@B82?2D6BDEDEA9E3E?82?A2?;2?8<@=@>E52B2D6B9252AA2?;2?886=@>32?83E?H:A252A6B:CD:G2B6C@?2?C:<@=2>E52B252A2D5:DE=:CC63282:36B:<ED
N
#6D6B2?82?
A2?;2?8<@=@>E52B2<6N A2?;2?886=@>32?83E?H:":<27B6<E6?C:82BAED2=25:<6D29E:46A2DB2>32D86=@>32?83E?H:82BAED2=252A2D 5:D6?DE<2? >6=2=E: A6BC2>22?$ 82B ?52 52A2D>6?82A=:<2C:<2?AB@C6CA6?8E<EB2?46A2DB2>32D3E?H:5:E52B236B52C2B<2?<@?C6AB6C@?2?C:3E?H:A252<@=@>E52B2=2<E<2?=292<D:F:D2C36B:<EDGambar 3.14Sebuah kolom udara di ataspermukaan air digetarkan olehsebuah garputala.
Gelombang Bunyi656B52C2B<2?2<D:F:D2CD6BC63ED?522<2?>6?52A2D<2?52D2A2?;2?8<@=@>E52B2#6>E5:2?3282:>2?2<2942B2>6?89:DE?846A2DB2>32D3E?H:5:E52B2(6B92D:<2?<6>32=: '34#/##0 9 ? ":<2?52>6?89:DE?8C6=:C:9152?02<2?5:52A2D<2?NN N'=69<2B6?2A2?;2?886=@>32?8CE5295:<6D29E:?5252A2D>6?89:DE?846A2DB2>32D?H236B52C2B<2?A6BC2>22?$
N #6D6B2?82?$46A2DB2>32D3E?H:> CA2?;2?886=@>32?882BAED2=2>7B6<E6?C:82BAED2=2 INilai frekuensi setiap garputalasudah diketahui. Analoginyaseperti nilai fokus dari lensa.Ingatlah5.Berhentilah memompa air pada saat terdengar bunyi mendengung. Ukurpanjang kolom saat itu dan catat sebagai l1 (resonansi pertama) pada tabelpengamatan seperti berikut.6.Turunkan permukaan air dalam lampu neon sampai terdengar bunyimendengung lagi. Ukur panjang kolom saat itu dan catat sebagai l2(resonansi kedua) pada tabel pengamatan.7.Ulangi langkah tersebut sampai didapatkan l3, l4, dan seterusnya.Data Pengamatan Resonansi Udara untuk Percobaan Cepat Rambat UdaraResonansi ke–nPanjang Kolom Udara ( )1.2.3.............(25282>32BD2>A2<C63E29<@=@>E52B2H2?8A2?;2?8?H2E?DE<>6?892C:=<2?B6C@?2?C:<@=@>E52B2C642B2F6BD:<2=":<2<@=@>E52B2D6BA6?56<>6?892C:=<2?B6C@?2?C:C22D 4>D6?DE<2?7B6<E6?C:82BAED2=2+6?DE<2?AE=2A2?;2?8<@=@>E52B2A252B6C@?2?C:C6=2?;ED?H2 :<6D29E:46A2DB2>32D3E?H:5:E52B2$
> C#7#$ :<6D29E: 4>
>$
> C(252A6B:CD:G2B6C@?2?C:A6BD2>252=2><@=@>E52B236B=2<E9E3E?82?36B:<ED2D2E 4>4>
> Contoh 3.10
Mudah dan Aktif Belajar Fisika untuk Kelas XII66F. Energi Gelombang Bunyi+6=29?52<6D29E:329G286=@>32?8252=2986D2B2?H2?8>6B2>32D>6=2=E:I2DA6B2?D2B2>65:E>D6D2A:>65:E>?H2D:52<:<ED>6B2>32D 2=2>A6B2>32D2??H286=@>32?8>6>:?529<2?6?6B8:52B:C2DED6>A2D<6D6>A2D=2:? ?6B8:86=@>32?83E?H:H2?85:D:>3E=<2?52B:CE2B2A6C2G2D;6D!# ! 52A2D>6>6429<2?<242;6?56=2CE2DE32?8E?2? 2=D6BC63ED>6?E?;E<<2?329G26?6B8:86=@>32?83E?H:>6=2<E<2?A6B2>32D2? ?6B8:86=@>32?83E?H:52A2D5:D6?DE<2?52B:6?6B8:A@D6?C:2=>2<C:>E>86D2B2?<2B6?23E?H:>6BEA2<2?86=@>32?8=@?8:DE5:?2=92C:=A6B2>32D2?86D2B2?'=69<2B6?2:DE6?6B8:86=@>32?83E?H:52A2D5:?H2D2<2?56?82?H2:DEC63282:36B:<ED
<2B6?2 Tes Kompetensi Subbab E'3,#-#0.#*&#.#/$6-6.#5+*#0 (252C6ED2C52G2:H2?8A2?;2?8?H2 >56?82?>2CC2
8A6B2>32D2?86=@>32?8DB2?F6BC2=H2?85:92C:=<2?>6>:=:<:<646A2D2?
> C+6?DE<2?D682?82?52G2:D6BC63ED +2=:H2?8A2?;2?8?H2>5:D682?8<2?56?82?82H2 &(6B2>32D2?86=@>32?8DB2?CF6BC2=H2?85:92C:=<2?>6>:=:<:<646A2D2?
> C+6?DE<2?>2CC2D2=:D6BC63ED
E2ED2CD2=:H2?8C2>2A2?;2?85:D2B:<@=6982H2H2?8C2>2%2CC2D2=:A6BD2>2<2=:>2CC2D2=:<65E2+2=:A6BD2>25:86D2B<2?56?82?7B6<E6?C:
IC652?8<2?D2=:<65E2
I":<2A2?;2?886=@>32?8A252D2=:A6BD2>24>D6?DE<2?A2?;2?886=@>32?8A252D2=:<65E2 *63E2986=@>32?8C:?EC>6B2>32DA252D2=:H2?8A2?;2?8?H2
4>36B86B2<52B:C:>A2?82?>:?:>E><6>2<C:>E>*E2DED:D:<>6>6B=E<2?G2<DE
C6<@?52=2>86B2<D6BC63ED+6?DE<2?2 A6B:@5686=@>32?83 7B6<E6?C:86=@>32?84 82H2D682?8D2=:;:<25:<6D29E:A2?;2?886=@>32?8
>52?>2CC2D2=:
8B2> *63E29A:A2@B82?2D6B3E<2A2?;2?8?H2
4>+6?DE<2?7B6<E6?C:?25252C2BH2?85:92C:=<2?A:A2D6BC63ED;:<246A2DB2>32D3E?H:5:E52B2
> C *63E29A:A2@B82?2D6BDEDEAA2?;2?8?H2 4>+6?DE<2??25252C2BH2?85:92C:=<2?A:A2:DE;:<246A2DB2>32D3E?H:5:E52B2
> C +6?DE<2?A2?;2?8>:?:>E>A:A2@B82?2D6B3E<2H2?836B6C@?2?C:56?82?82BAED2=2H2?836B86D2B56?82?7B6<E6?C:
I;:<246A2DB2>32D3E?H:5:E52B2
> CKata Kunci• resonansi• Hukum Mersenne• pipa organa• Hukum I Bernoulli• Hukum II Bernoulli
> C
I
>$"25:7B6<E6?C:82BAED2=2252=29
I(2?;2?8<@=@>E52B2A252B6C@?2?C:<65E2 52?<6D:82 52A2D5:D6?DE<2?56?82? '34#/##0 9 H2:DE 52?E?DE<B6C@?2?C:<65E2 252=29
>
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>
Gelombang Bunyi67Gambar 3.15Sumber bunyi berupa titik.Semakin jauh dari sumber bunyi,luas permukaan semakin besar.Pr1r22D2E >2<25:A6B@=69
N #6D6B2?82? >2CC2A2BD:<6=<8 2>A=:DE5@86=@>32?8>7B6<E6?C:86D2B I<@?CD2?D2A682C& >6B52C2B<2? '34#/##0 9
6?6B8:H2?85:A:?529<2?@=69CE2DE86=@>32?8C632?5:?856?82?<E25B2D2>A=:DE5@?H21.Intensitas Gelombang Bunyi!?D6?C:D2C86=@>32?83E?H:5:567:?:C:<2?C63282:;E>=296?6B8:3E?H:A6BC2DE2?G2<DEH2?8>6?6>3ECD682<=EBECCE2DE3:52?8A6BC2DE2?=E2C E3E?82?2?D2B252H2=E2C52?:?D6?C:D2C3E?H:>6>6?E9:A6BC2>22?
N #6D6B2?82? :?D6?C:D2C86=@>32?83E?H:- >=E2CA6?2>A2?8>52H286=@>32?83E?H:-*E>36B3E?H:36BEA2C63E29D:D:<C6A6BD:A252#/$#3
2<2?>6>2?42B<2?3E?H:<6C682=22B29BD:?H286=@>32?83E?H:>6B2>32D52=2>D:825:>6?C: 2=H2?8C2>2D6B;25:AE=2A25286=@>32?84292H2!?D6?C:D2C3E?H:A2523:52?8A6B>E<22?52=2>3@=2H2?8>6>:=:<:;2B:;2B:2<2?>6>:=:<:=E2C 2?882AD:52<2526?6B8:3E?H:H2?89:=2?82D2ED6BC6B2AC6=2>2A6B2>32D2?!?D6?C:D2C3E?H:2<2?C6>2<:?<64:=;:<2;2B2<CE>36B3E?H:<6CE2DE3:52?8A6B>E<22?C6>2<:?;2E9(6?8EB2?82?:?D6?C:D2C3E?H:2<:32DA6BD2>3292?;2B2<52B:CE>36B3E?H:>6>6?E9:9E3E?82?36B:<ED
N #6D6B2?82?;2B2<CE>36B3E?H:<6A@C:C:3:52?8 >;2B2<CE>36B3E?H:<6A@C:C:3:52?8 >6B52C2B<2? '34#/##0 9 52A2D5:?H2D2<2?329G2:?D6?C:D2C3E?H:36B32?5:?8D6B32=:<56?82?<E25B2D;2B2<CE>36B3E?H:D6BC63ED<63:52?8A6?56?82B2?2.Taraf Intensitas (TI)*6D:2A>2<9=E<5:2=2>C6>6CD2:?:>6>:=:<:32D2C:?D6?C:D2CA6?56?82B2?2D2C:?D6?C:D2C3E?H:H2?852A2D5:56?82BD6=:?82>2?EC:2252=29C63282:36B:<ED1 bel (B) = 10 desibel (dB)IngatlahTugas Anda 3.4Berapakah rasio intensitas bunyi 90dB terhadap intensitas bunyi 60 dB?
Mudah dan Aktif Belajar Fisika untuk Kelas XII68+2B27:?D6?C:D2C3E?H:C63E29A6C2G2DA252;2B2<
>252=29
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>#7#$ :<6D29E:
>
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5!?D6?C:D2C3E?H:36B32?5:?8D6B32=:<56?82?<E25B2D;2B2< 56?82?>6?88E?2<2? '34#/##0 9 E?DE< 52? 5:A6B@=69
=@8
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=@8 =@8 Suatu gelombang gempa terasa diMalang dengan intensitas 6 × 105 W/m2.Sumber gempa berasal dari suatutempat yang berjarak 300 km dariMalang. Jika jarak antara Malang danSurabaya sebesar 100 km dan ketigatempat itu membentuk segitigasiku-siku dengan sudut siku-siku diMalang, maka intensitas gempa yangterasa di Surabaya adalah ....a.2 × 105 W/m2b.3 × 105 W/m2c.4,5 × 105 W/m2d.5,4 × 105 W/m2e.7,5 × 105 W/m2 UMPTN 1996Pembahasan: 2221121122IrrIIIrr 252530061010I= 5,4 × 105 W/m2Jawaban: dSurabayaMalangsumber gempa300 km100 kmContoh 3.11Pembahasan Soal2 !?D6?C:D2CD6B<64:=H2?8>2C:952A2D>6?:>3E=<2?B2?8C2?82?A6?56?82B2?A252D6=:?82252=29C636C2B
N G2DD >H2?85:C63EDC63282: " !"! 3 !?D6?C:D2CD6B36C2BH2?8>2C:9>2>AE5:D6B:>2D6=:?82>2?EC:2D2?A2B2C2C2<:D252=29C636C2B G2DD >H2?85:C63ED"! "25:32D2CA6?56?82B2?D6B6?529252=29
N G2DD >52?32D2C:?D6?C:D2CD6BD:?88:252=29 G2DD >+2B27:?D6?C:D2C C632?5:?856?82?=@82B:D>2A6B32?5:?82?2?D2B2:?D6?C:D2C3E?H:52?92B822>32?8:?D6?C:D2C3E?H:H2?8D6B56?82B52?>6>:=:<:C2DE2?56C:36=5*642B2>2D6>2D:C9E3E?82?2?D2B252? 5:DE=:C
=@8
N #6D6B2?82? D2B27:?D6?C:D2C5:?D6?C:D2C3E?H:- >
N - > :?D6?C:D2C2>32?8A6?56?82B2?6B:<ED:?:52D2:?D6?C:D2C52?D2B27:?D6?C:D2C52B:3636B2A2CE>36B3E?H:>32?8A6?56?82B2? Q
N >32?8B2C2C2<:D*:B:?6A252;2B2<
> Q
N $2=E=:?D2CB2>2:
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4>
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!?D6?C:D2C52?+2B27!?D6?C:D2C52B:636B2A2*E>36BE?H:05'04+5#4"/ 6/$'3608+ #3#(05'04+5#4&Sumber:College Physics, 1980
Gelombang Bunyi69*63E29CE>36B3E?H:>6?892C:=<2?D2B27:?D6?C:D2CC636C2B
56B2A2D2B27:?D6?C:D2CH2?85:92C:=<2?;:<2D6B52A2D
CE>36B3E?H:H2?8C2>252?36B3E?H:A252C22D36BC2>22?#7#$ :<6D29E:
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=@8
N #6D6B2?82? D2B27:?D6?C:D2C@=69 3E29CE>36B 32?H2<?H2CE>36B D2B27:?D6?C:D2C@=69 3E29CE>36B
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>252=29
5Kata Kunci• energi gelombang bunyi• intensitas gelombang• taraf intensitas• batas ambang pendengaran *63E29CE>36B3E?H:>6>:=:<:D2B27:?D6?C:D2CC636C2B 5":<2
3E29CE>36B3E?H:H2?8C2>236B3E?H:C6B6?D2<36B2A2D2B27:?D6?C:D2C3E?H:H2?85:92C:=<2? 6B2A2A6B32?5:?82?:?D6?C:D2C5E2CE>36B3E?H:;:<2D2B27:?D6?C:D2C?H2 5
*63E29CE>36B3E?H:D:D:<56?82?52H2 G2DD>6>2?42B<2?86=@>32?83E?H:36BEA286=@>32?8C76B:C3@=2+6?DE<2?D2B27:?D6?C:D2C3E?H:H2?85:56?82B@=69C6C6@B2?8A252;2B2<
>6D6B52B:CE>36B3E?H:D6BC63ED
N G2DD > *63E29CE>36B3E?H:>6>:=:<:D2B27:?D6?C:D2C36==":<2
3E29CE>36B3E?H:H2?8C2>236B3E?H:C642B2C6B6?D2<36B2A2<29D2B27:?D6?C:D2C3E?H:H2?85:92C:=<2?$5#0#4
*63E29CE>36B3E?H:>6>2?42B<2?6?6B8:<6C682=22B29A23:=2;2B2<A6?56?82BD6B9252ACE>36B3E?H:5:3E2D>6?;25:<2=:C6>E=236B2A2A6?8EB2?82?D2B27:?D6?C:D2C3E?H:H2?8D6B56?82BTes Kompetensi Subbab F'3,#-#0.#*&#.#/$6-6.#5+*#0
Mudah dan Aktif Belajar Fisika untuk Kelas XII70Rangkuman 6=@>32?83E?H:252=2986=@>32?8=@?8:DE5:?2=H2?852A2D>6B2>32D52=2>>65:E>I2DA252D42:B52?82C 6A2DB2>32D3E?H:5:E52B236B82?DE?8A252;6?:CA2BD:<6=A6>36?DE<E52B2H2?85:?H2D2<2?56?82?$C652?8<2?5:52=2>I2DA252D36B82?DE?8A252>@5E=EC.@E?852?>2CC2;6?:CI2D$52AE?5:52=2>I2D42:B36B82?DE?8A252>@5E=ECE=<52?>2CC2;6?:CI2D42:B$
+:?88:B6?529?2523E?H:36B82?DE?8A2527B6<E6?C:3E?H:#E2D3E?H:36B82?DE?8A2522>A=:DE5@86D2B2? E5:@C@?:<252=293E?H:H2?836B7B6<E6?C:2?D2B2
IC2>A2:56?82?
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IC652?8<2?E=DB2C@?:<252=293E?H:H2?836B7B6<E6?C:5:2D2C
I 6=@>32?83E?H:52A2D>6?82=2>:AB@C6C5:CA6BC:B67B2<C:B67=6<C:5:7B2<C::?D6B76B6?C:52?A@=2B:C2C: !?D6B76B6?C:86=@>32?83E?H:D6B;25:;:<23652=:?D2C2?86=@>32?8?H2>6BEA2<2?<6=:A2D2?3:=2?82?3E=2D52B:C6D6?829A2?;2?886=@>32?83E?H:
! (6BC2>22?CEA6BA@C:C:86=@>32?83E?H: 4@C C:? &"" B6<E6?C:52??25252C2BA25252G2:5:?H2D2<2?56?82?A6BC2>22? C652?8<2?7B6<E6?C:?2522D2C<6 A25252G2:5:?H2D2<2?56?82?A6BC2>22? (252A:A2@B82?2D6B3E<27B6<E6?C:?2522D2C<6 5:?H2D2<2?56?82?A6BC2>22? $ C652?8<2?A252A:A2@B82?2D6BDEDEA7B6<E6?C:?2522D2C<6 5:?H2D2<2?56?82? $
E3E?82?A2?;2?8<@=@>E52B2D6B9252AA2?;2?886=@>32?83E?H:A252A6B:CD:G2B6C@?2?C:<@=@>E52B2252=29 2=2>A6B2>32D2??H286=@>32?83E?H:>6>:?529<2?6?6B8:C636C2B
&56?82?& 252=292>A=:DE5@86=@>32?8 *6>2<:?;2E9;2B2<CE>36B3E?H:D6B9252AA6?56?82B:?D6?C:D2C3E?H:2<2?C6>2<:?<64:=
!?D6?C:D2C3E?H:5:?H2D2<2?56?82?A6BC2>22?
=@8 ":<2D6B52A2D 3E29CE>36B3E?H:D2B27:?D6?C:D2C3E?H:D@D2=?H25:?H2D2<2?56?82?A6BC2>22? ?
=@8
Gelombang Bunyi71Peta Konsep#=2C:7:<2C: 6=@>32?8E?H:6A2D)2>32D*:72D*:72D 6=@>32?8E?H:/2D(252D$/2D2:B$ 2C$!?D6B76B6?C:(6>2?DE=2? :7B2<C:(6=2H2?82?!?D6?C:D2CE?H:+2B27!?D6?C:D2C;:<2CE>36B3E?H:?H232?H2<>6>3292C'.1/$#0)608+>6>3292C
=@8 >6>3292C+:?88:E?H:#E2DE?H:-2B?2E?H:Setelah mempelajari bab ini, Anda tentu dapatmengetahui sifat-sifat dasar gelombang bunyi danklasifikasi gelombang bunyi serta dapat menjelaskanperistiwa resonansi pada pipa organa. Dari materi babini, bagian manakah yang Anda anggap sulit? Cobadiskusikan dengan teman atau guru Fisika Anda.RefleksiPada bab ini pula, Anda telah mempelajari manfaatdari gelombang bunyi, seperti untuk mengukurkedalaman laut. Coba Anda sebutkan manfaat lain yangAnda rasakan setelah mempelajari bab ini.52=2>
Mudah dan Aktif Belajar Fisika untuk Kelas XII72 (252CE2DEC22DD6B=:92D<:=2D52?
56D:<<6>E5:2?D6B56?82BCE2B28E?DEB?H2":<236C2B<646A2D2?4292H2
Q
> C52?<646A2D2?3E?H:
> C;2B2<2?D2B2D6>A2D2C2=<:=2D52?A6?82>2D2
>5
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> *63E292=2DC@?2B5:8E?2<2?E?DE<>6?8E<EB<652=2>2?=2ED*6=2?8G2<DEH2?85:42D2D@=69C@?2BE?DE<86=@>32?8>6B2>32D9:?882<6>32=:=28:<6C@?2B252=29 C6<@?":<246A2DB2>32D86=@>32?85:52=2>2:B=2ED252=29
> C<652=2>2?=2EDD6BC63ED252=292
>5
>3
>6
>4
>
E23E29CE>36B3E?H:C6A6BD:D2>A2<A25282>32B36B:<ED36B86D2BC642B2<@96B6?E?H:H2?8?H2B:?85:92C:=<2?5:;:<2 6?82?>6?2:<<2?C642B2A6B=292?=292?3E?H:D6B=6>295:56?82B<6D:<2 N252=29
4>
4>52?
4>":<246A2DB2>32D3E?H:5:E52B2
> C36C2B7B6<E6?C:3E?H:252=292
I5
I3 I6
I4
I E23E29 #! 52?5:=6D2<<2?C6A6BD:A25282>32B36B:<ED+6B?H2D2A25256D6<D@B D6B;25::?D6B76B6?C:>2<C:>E>@B56A6BD2>2":<2<646A2D2?3E?H:5:E52B2
> C7B6<E6?C:86=@>32?83E?H:D6BC63EDD6BC63ED252=292 I5
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8B2> 4>
252=29 Q
& >6A2DB2>32D86=@>32?852=2>I2D42:BD6BC63ED252=292
> C5
> C3
> C6
> C4
> C *63E29CE>36B3E?H:36B7B6<E6?C: < I36B86B2<=2?8CE?8<62B29C6@B2?8A6?56?82B56?82?<6=2;E2?
<2=:<6=2;E2?3E?H: B6<E6?C:3E?H:H2?85:D6B:>2?H2252=292
< I5
< I3 < I6
< I4 < I 1#.!9!
?52C652?836B86B2<>6?56<2D:C63E29CE>36B3E?H:*D:52<36B86B2<H2?836B252;2E95:56A2??5252?C652?8>6>2?42B<2?3E?H:36B7B6<E6?C:
<6C682=22B2982<;2E95:36=2<2?8?52D6B52A2DC63E295:?5:?8A6>2?DE= E?H:H2?8?5256?82B=2?8CE?852B:*56?82?7B6<E6?C:C52?H2?836B2C2=52B:A2?DE=2?5: 56?82?7B6<E6?C:5<6D:<236B:?D6B2<C:5:D6=:?82?52252=292 D:52<2<2?>6?:>3E=<2?=2H2?82?<2B6?2C53 D:52<2<2?>6?:>3E=<2?=2H2?82?<2B6?2C54 2<2?>6?:>3E=<2?=2H2?82?52?>6>6?E9:C55 2<2?>6?:>3E=<2?=2H2?82?52?>6>6?E9:C
56 2<2?>6?:>3E=<2?=2H2?82?52?>6>6?E9:C5 *63E29CE>36B3E?H:36B86B2<56?82?<646A2D2?> C>6?E;E<6A6?56?82BH2?85:2>C69:?8827B6<E6?C:H2?85:56?82B@=69A6?56?82B252=29":<2CE>36B3E?H:D6BC63ED5:2>C652?8<2?A6?56?82B36B86B2<56?82?<646A2D2?> C>6?56<2D:CE>36B3E?H:7B6<E6?C:H2?85:56?82B@=69A6?56?82B252=29":<246A2DB2>32D3E?H:5:E52B2$> CA6B32?5:?82? 252=292 5 N$3 N$6 $4 $ *6@B2?8A6?6B32?8H2?8A6C2G2DD6B32?8?H2>6?E;E<6>6?2B232?52B2>6?56?82B3E?H:C:B:?6>6?2B256?82?7B6<E6?C:
I":<2C22D:DEC:B:?6D6BC63ED>6>2?42B<2?3E?H:56?82?7B6<E6?C:
I52?46A2DB2>32D3E?H:5:E52B2
> C<646A2D2?A6C2G2DD6B32?8D6BC63ED252=292
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Gelombang Bunyi73
(6=2H2?82?3E?H:D6B;25:<2B6?2252?H2:?D6B76B6?C:2 =63:952B: 86=@>32?8H2?8C2>27B6<E6?C:?H23 86=@>32?8H2?836B=2G2?2?2B2986D2B?H24 86=@>32?8H2?8C2>27B6<E6?C:?H25 86=@>32?8H2?836C2B36527B6<E6?C:?H26 86=@>32?8H2?8<64:=36527B6<E6?C:?H2 ":<25E23E29CE>36B3E?H:>2C:?8>2C:?856?82?7B6<E6?C:
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4>52?36B86D2BA252?2522D2C<65E246A2DB2>32D86=@>32?8DB2?CF6BC2=52=2><2G2D252=2946A2DB2>32D3E?H:5:E52B2
> C2 > C3
> C4
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E23E2952G2:32;2H2?8:56?D:<>6>36B:<2??25252C2B56?82?7B6<E6?C:
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I5 I3 I6 I4 I *63E29D23E?886=2CB6C@?2?C:H2?836B:C:2:B>6>:=:<:=E2CA6?2>A2?8
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4>
2:B5:3E2?8<6=E2BC69:?882D6B;25:B6C@?2?C:<65E2":<2<6=2;E2?3E?H:5:E52B2
> C7B6<E6?C:82BAED2=2H2?85:A2<2:252=292
I5
I3
I6
4
I (252A6B4@322?%6=565:8E?2<2?C6ED2C36?2?8H2?8A2?;2?8?H2 >6D6B52?36B>2CC28B2>":<23632?C636C2B
<85:82?DE?8<2?A25236?2?8D6BC63ED<646A2D2?A6B2>32D2?86=@>32?8A25236?2?8252=29
> C2 > C5 > C3
> C6
> C4
> C *6ED2C52G2:>6?892C:=<2??25252C2B":<252G2:D6BC63ED5:A6?56<<2?4>D2?A2>6?8E329D682?82?5:92C:=<2?7B6<E6?C: ":<252G2:5:A6?56<<2? 4>=28:7B6<E6?C:H2?85:92C:=<2?252=2925 3 6
4
*6ED2C52G2:H2?8A2?;2?8?H2
4>52?36B>2CC2 8B2>5:;6A:D<65E2E;E?8?H252?5:B6?D2?8<2?56?82?D682?82?
& B6<E6?C:?2522D2CA6BD2>2H2?85:92C:=<2?252=292 I5
I3
I6
I4
I 1,2 mf = 340 HzW#6D:<282BAED2=25:86D2B<2?A25252G2:D6B;25:86=@>32?8CD2C:@?6BC6A6BD:D2>A2<A25282>32B#646A2D2?B2>32D86=@>32?8A25252G2:252=292
> C5
> C3
> C6
> C4
> C *63E29A:A2@B82?2D6BDEDEA>6>:=:<:A2?;2?8
4>":<246A2DB2>32D3E?H:5:E52B2
> C36C2B7B6<E6?C:?2522D2C<65E2252=292
I5
I3
I6 I4 I
&2522D2CA6BD2>2A:A2@B82?2D6B3E<2H2?8A2?;2?8?H2
4>36B6C@?2?C:56?82?A:A2@B82?2D6BDEDEA":<2A252C22D36B6C@?2?C:;E>=29C:>AE=A252<65E2A:A2C2>2A2?;2?8A:A2@B82?2D6BDEDEAD6BC63ED52=2>4>252=292
5
3
6
4
! #810 (252A:A2@B82?2D6B3E<2?2522D2C<65E25:92C:=<2?A2?;2?886=@>32?8C636C2B%52?A252A:A2@B82?2D6BDEDEA?2522D2C<65E25:92C:=<2?A2?;2?886=@>32?8C636C2B&":<2A2?;2?8<65E2A:A2C2>2?:=2:A6B32?5:?82?&52?%252=292 3
4
5 6 +2B27:?D6?C:D2C3E?H:C63E29>6C:?B2D2B2D2
5":<2
>6C:?5:9:5EA<2?36BC2>2D2B27:?D6?C:D2C?H2252=292
53
54
55 56
5
Mudah dan Aktif Belajar Fisika untuk Kelas XII74 *63E2982BAED2=236B7B6<E6?C:
I5:86D2B<2?5:A6B>E<22?D23E?8B6C@?2?C:(252C22D<@=@>E52B2>6?42A2:<6D:?88:2? 4>D6B;25:B6C@?2?C:H2?8A6BD2>26B2A2<2946A2DB2>32D3E?H:C22D:DE *6ED2C<2G2DH2?8A2?;2?8?H2
4>5::<2D<65E2E;E?8?H2#6>E5:2?<2G2D5:86D2B<2?=@?8:DE5:?2=6A2DB2>32D86=@>32?8H2?85:92C:=<2?
> C%@5E=EC.@E?8<2G2D Q
& > :DE?8=292 7B6<E6?C:86D2B?H23 >2CC2;6?:C<2G2D
%@3:=>6?56<2D:A6?82>2D5:2>56?82?<646A2D2?
> CC2>3:=>6>3E?H:<2?C:B6?636B7B6<E6?C:
I(252C22D:DE;E82>@3:=>6?56<2D:52B:2B29H2?836B=2G2?2?56?82?A252<646A2D2?
> CC2>3:=>6>3E?H:<2?C:B:?636B7B6<E6?C: I":<246A2DB2>32D3E?H:5:E52B2C22D:DE
> C36B2A2<297B6<E6?C:=2H2?82?H2?85:56?82B@=69 *6ED2C<2G2D32;2H2?8>2CC2?H2852?A2?;2?8 >5:36B:D682?82?&+6?DE<2?2 46A2DB2>32DA2?;2?886=@>32?8DB2?CF6BC2=C6A2?;2?8<2G2D3 A2?;2?886=@>32?852?7B6<E6?C:?25252C2B?H24 7B6<E6?C:?2522D2C<6C2DE52?<65E2 B6<E6?C:?2522D2CA6BD2>252B:A:A2@B82?2D6B3E<2
I":<246A2DB2>32D3E?H:5:E52B2
> C9:DE?8=292 7B6<E6?C:?25252C2B?H23 7B6<E6?C:?2522D2C<6D:82 6A2DB2>32D3E?H:52=2>C63E29A:A2@B82?2252=29
> C":<27B6<E6?C:?25252C2BA:A2@B82?2252=29
I36B2A2A2?;2?8>:?:>E>A:A2@B82?2E?DE<<2CEC2 A:A2@B82?2D6B3E<23 A:A2@B82?2D6BDEDEA E2ED2C52G2:32;2C6;6?:C>6>36B:<2??25252C2B
I":<2A2?;2?8C2=29C2DE52G2:5:D2>329 36B2A2<297B6<E6?C:=2H2?82?H2?8D6B;25: E2ED2C52G2:32;2H2?8:56?D:<>6>36B:<2??25252C2B56?82?7B6<E6?C:
I":<2D682?82?52=2>C2=29C2DE52G2:5:D2>329 36B2A27B6<E6?C:=2H2?82?52G2:H2?8>E?8<:? *66<@BD2G@?H2?8>6?56?8E?8A252;2B2< >>6>:=:<:D2B27:?D6?C:D2C
5":<2252
D2G@?>6?56?8E?8A252;2B2<%D2B27:?D6?C:D2C?H2
5D6?DE<2?;2B2<%
(252C63E29D23E?8B6C@?2?C:D6B52A2D<@=@>E52B2A252"*6=:C:9A2?;2?8<@=@>B6C@?2?C:
4>#646A2D2?3E?H:A252CE9E
L252=29
> C :DE?8";:<27B6<E6?C:B6C@?2?C:
I #7#$.#*2'35#08##0$'3+-65&'0)#05'2#5
":<2C63E29C6A652>@D@B>6=6G2D:C6C6@B2?8>@D@BD6BC63ED2<2?>6?:>3E=<2?D2B27:?D6?C:D2C+!C636C2B
5":<2@B2?8D6BC63ED5:=6G2D:
C6A652>@D@B;6?:CH2?8C2>2C6<2=:8ECD2B27:?D6?C:D2C?H2252=292 55
53
56
54
5 +2B27:?D6?C:D2C3E?H:C63E29>6C:?252=29
556?82?24E2?:?D6?C:D2C2>32?8A6?56?82B2?C636C2BN - >":<2D2B27:?D6?C:D2C5:52=2>BE2?8A23B:<H2?8>6?88E?2<2?C6;E>=29>6C:?D6BC63ED252=29
5;E>=29>6C:?H2?85:8E?2<2?252=292
5
3
6
4
+2B27:?D6?C:D2C3E?H:A252C63E29;6?56=2D6B3E<2H2?8=E2C?H2 >252=29
5":<2?:=2:2>32?83E?H:
N - 4>52H22<ECD:<H2?8>2CE<>6=2=E:;6?56=2D6BC63ED252=292
N -3
N -4
N
-5
N-6
N-