Gaya Sentripetal F Gaya Memengaruhi Gerak Benda

89 Dinamika Gerak T r T 5E236?52H2?836BC6?DE92?32?H25:;EA2:52=269:5EA2?C692B:92B: 2523636B2A22CEC82H286C62?36BC:72D6BE8:2?C652?82?A252 2CECH2?8=2:?82H286C62?36BC:72D6?8E?DE?82? ,6B2?8C:CG26 ?6?52?8C63E293=25:2D2C=2A2?82?36BEAEDD6B;25:82H286C62?2?D2B2 A6BE22?3=256?82?92A2B2?BEAEDC69:?8823=222?36B96?D: A252;2B2H2?8D:52D6B=2=E;2E9 2H286C62?6?89232D=2;E3=2 2524?D9=2:?82H286C62?D:3E=2?D2B232?6?52B22?H2?8 C652?836B86B256?82?;2=2?H2?85:=2=E:?H2C69:?882D:52C=:A 2H2 86C62? E52B2 56?82? C6B2?8 A6?6B;E? A2HE?8 D6B;25: C6A2?;2?8 86B22??H2 3EC2?E52B2H2?86?H6?DE93:52?8A2HE?86BEA22? 82H2A6?89232DD6B9252A=2;EA6?6B;E?C69:?882A6?6B;E?C6=22DC22D D:325:D2?29 252A6B:CD:G2:?:82H286C62?C2?82D36B2?722DD6B9252A 6C6=22D2?A6?6B;E?A2HE?8

6. Gaya Sentripetal F

sp -6=29?526D29E:329G2646A2D2?252=2936C2B2?F6DBH2?8 6:=::36C2B52?2B29 :22B2952?6=2;E2?36BE329F6DB646A2D2? 22? 36BE329 ;E82 6BE3292? F6DB 646A2D2? 22? 6?:3E=2? A6B46A2D2? 6?EBEDEE6GD?82H26BEA22?A6B2=:2?2?D2B2 2CC236?5256?82?A6B46A2D2?H2?85::=::36?52D6BC63ED :282H2 C6?DB:A6D2=H2?8366B;2A25236?5236B86B26=:?82B36B2DEB2?252=29 A6B46A2D2?C6?DB:A6D2=H2?85::=::36?5236B2CC2252=29 22 82H2C6?DB:A6D2=5:BEEC2?C63282:36B:ED Gambar 5.6 Gerak turun penerjun payung semakin lambat ketika semakin dekat dengan tanah. Sumber: Physics for You, 2001 + 2 2 2H2C6?DB:A6D2=2B29?H2C6=2=E6?E;E6D:D:AEC2D=:?82B2?52? D682=EBEC56?82?F6DB646A2D2??H2 .?DE6?86D29E:252?H282H2 C6?DB:A6D2=A25286B26=:?82B36B2DEB2?=2E2?68:2D2?36B:ED Aktivitas Fisika 5.4 Gaya Sentripetal Tujuan Percobaan Mengetahui arah gaya sentripetal Alat-Alat Percobaan Tali dan bola pingpong Langkah-Langkah Percobaan 1. Ikatkan ujung tali pada bola pingpong. 2. Putar bola tersebut di atas kepala dengan posisi mendatar. 3. Apa yang Anda rasakan terhadap gaya tegangan tali? 4. Putarlah tali lebih cepat lagi. Adakah pengaruh kelajuan bola dengan gaya tegangan tali? 5. Apa kesimpulan Anda dari percobaan ini? 6B92D:2? + :2 82H2 36B2D 3=2 5:232:2? 8232B D6BC63ED6A6B=:92D2?82H282H2H2?8366B;2A2523=2H2?85::2D 56?82?D2=:52?5:AED2B56?82?D2?82?C63282:D:D:AEC2D?H2 2A2D 5:2D22?329G23=2D6BC63ED36B86B26=:?82B 2H2D682?82?D2=: 6BEA22? 82H2 H2?8 6?H63232? 36?52 D6BC63ED 36B86B2 6=:?82B Gambar 5.7 Gaya sentripetal menuju pusat lingkaran. N Di unduh dari : Bukupaket.com 90 Mudah dan Aktif Belajar Fisika untuk Kelas X ,63E293=236C:36B2CC285::2D56?82?C6ED2CD2=:H2?8A2?;2?8?H24 6E5:2?5:AED2B636?DE=:?D2C2?6=:?82B56?82?6=2;E2? C -6?DE2? 82H2C6?DB:A6D2=3=236C:D6BC63ED 4 :6D29E: 88 4 + C R = 80 c m m = 50 g Contoh 5.4 C 0 + , 652A2D5:DE=:CC63282:36B:ED + 6B=E ?52 A6B92D:2? 329G2 82H2 C6?DB:A6D2= 6BEA22? CE2DE :CD:=29E?DEB6CE=D2?82H2H2?82B29?H26?E;EAEC2D 2H2C6?DB:A6D2=;E8252A2D?52D6E:A25286B26=:?82B36?52 36?52=2?8:DD6B9252A36?52=2?8:D=2:??H2 ,63282:4?D93E=2?H2?8 C6=2=E6?86=:=:?8:E: 6?82A2 E=2? C6=2=E 6?86=:=:?8: E: 2H2 2A229 H2?8 36BD:?52C63282:82H2C6?DB:A6D2=2B:EE6GD?5:6D29E:329G2 2?D2B25E23E2936?52H2?86:=::2CC252?5:A:C292?=69;2B2 D6BD6?DE 366B;2 C63E29 82H2 D2B:6?2B: H2?8 36C2B?H2 C632?5:?8 56?82? 2CC2 36?5236?52 D6BC63ED 52? 36B32?5:?8 D6B32=: 56?82? E25B2D;2B2A:C292?D2B236?5236?52D6BC63ED 2H2:?:5:C63EDC63282: 82H28B2F:D2C: 2H2:?:=29H2?86?H63232?E=2?36B86B26?86=:=:?8: E: 25: H2?8 36BA6B2? C63282: 82H2 C6?DB:A6D2= A252 86B2 E=2? 6?86=:=:?8:E:252=2982H28B2F:D2C:2?D2B2E=2?52?E: N ?52D6=296?86D29E:329G286B23E=2?5:A6?82BE9:82H2D2B:E: :DE?8=29 36C2B82H2D2B:E:D6B9252A3E=2?D6BC63ED .?DE6?86B;22?DE82C:?:?52 A6B=E6?86D29E:36C2B2?36C2B2?E:52?3E=2?H2?85:3EDE92?52=2 A6B9:DE?82?D6BC63ED Mari Mencari Tahu 2H2C6?DB:A6D2=5:A6B=6956?82?6?88E?2 2?A6BC222? CA + 2 CA 2 4 ms 0,1kg 2 N 0,8 m 25:82H2C6?DB:A6D2=3=236C:252=29 Sebuah benda bermassa 200 gram diikat dengan tali ringan. Kemudian, diputar secara horizontal dengan kecepatan sudut tetap 5 rads. Panjang tali tersebut adalah 60 cm. Berapakah besar gaya sentripetal pada benda tersebut? a. 0,3 N b. 0,6 N c. 3 N d. 6 N e. 30 N UAN , 2001 Pembahasan Diketahui: m = 200 gram = 0,2 kg = 5 rads = 60 cm = 0,6 m F sp = 2 v m R Dalam kasus ini, = R. Dengan demikian, F sp = 2 v m R F sp = 2 m R F sp = 0,2 kg 5 rads 2 0,6 m F sp = 3 N Jadi, gaya sentripetal yang bekerja pada benda adalah 3 N. Jawaban: C Pembahasan Soal Kata Kunci • Hukum I Newton • Hukum II Newton • Hukum III Newton • gaya aksi • gaya reaksi • gaya gesekan • gaya sentripetal 2H2:?:;E8252A2D5:B2C22?=69D2?82??52 2H2D682?82? D2=::?:6BEA22?82H2H2?82B29?H26?E;EAEC2D52?A6?H6323 3=2D6BC63ED36B86B26=:?82B 2=292=:?:H2?836BA6B2?C63282: 82H2C6?DB:A6D2= 252=2982H2D682?82?D2=: Di unduh dari : Bukupaket.com 91 Dinamika Gerak

B. Penerapan Hukum Newton

252328:2?:?:?5222?6A6=2;2B:3636B2A2A6?6B2A2?9EE 6GD?52=269:5EA2?C692B:92B:

1. Gerak Benda pada Bidang Datar

,63E2936?52D6B=6D2A2523:52?852D2B=:4:?C6A6BD:A252 + 6E5:2? 5:36B: 82H2 6?52D2B 9:?882 36?52 36B86B2 =EBEC 56?82?A6B46A2D2? 2H282H2H2?8366B;2A252CE3E.252=29 . , 6?52D:5236B86B2D6B9252ACE3E.22 . , N , 2H2H2?8366B;2A252CE3E- - Tes Kompetensi Subbab A , +22 1 , :DE?882H2H2?85:3EDE92?C63E293:=H2?82CC2 ?H2 8E?DE6?42A2:646A2D2? C52=2 G2DEC ,63E2982H2366B;2A25236?5236B2CC2 52? A6B46A2D2?H2?85:D:3E=2? C 2H2H2?8C22 366B;2A25236?52=2:?36B2CC2 A6B46A2D2?H2?8 5:D:3E=2? C 2 6B2A229?:=2:B2C: 1 2 3 :2 52? 5:823E?836B2A2A6B46A2D2?H2?8 5:92C:=2?=6982H2 ,63E293EC2CC2?H2 836B86B256?82?6 46A2D2? ;2 3:=5:B652?36B96?D:C6D6=29 6?6AE9;2B2 -6?DE2?82H2B6H2?8 366B;2A2523:=D6BC63ED ?52C652?836B2525:52=2C63E29A6C2G2DD6B32?8 A2526D:?88:2? 2: 6B2A2A6B C6?29A6BE3292?36B2D3252??52 ,6AD?832DE32D2H2?82CC2?H2 8D6B=6D25:2 5:2D2CD2?29 6E5:2?32DED6BC63ED5:D2B:62D2C 56?82?82H2C6=22 C=2=E5:=6A2C2? :2 C D6?DE2? D:?88: 2C:E H2?8 5:42A2:?H2 ,63E293=236B2CC2 8B25::2DA252E;E?8 C6ED2CD2=:H2?8A2?;2?8?H24 =236BAED2B52 =2=:?82B2?9B:I?D2=56?82?6=2;E2?D6D2A C :DE?8D682?82?D2=: ,63E29A:B:?82?56?82?;2B:;2B:45:AED2B56?82? 646A2D2?CE5ED B25 C -6?DE2?A6B46A2D2?52? 82H2C6?DB:A6D2=C63E29D:D:36B2CC2 8H2?836B252 5:A:?88:BA:B:?82?D6BC63ED ,63E29 3=2 36B2CC2 8 5:AED2B 6?8:D2B: =:?82B2?F6BD:2=H2?8B25:EC?H256?82?=2;E C :DE?8D682?82?2C:E52?D682?82?:?: E D2=: H2?8 6?89E3E?82? 3=2 6 AEC2D =:?82B2?;:2 C ,63E296?52B22?6?:E?85:=:?D2C2?;2=2?6? 52D2B2C2B56?82?;2B:;2B:6=6?8E?82?2CC2 6?52B22? 52? A6?EA2?8 8 -6?DE2? 646A2D2?2C:E282B6?52B2?D:52C=:A;:282H2 86C62?2?D2B232?52?;2=2? ,63E293:=6=6G2D:;2=2?463E?8 :6D29E: B25:EC 2CC23:=36C6BD2A6?EA2?8?H2 8 2H2D62?3:=D6B9252A;2=2? :2 A6B46A2D2?8B2F:D2C: C D6?DE2?=2;E3:=A252 C22D65E5E2?D6BD:?88: Gambar 5.8 Gaya-gaya yang bekerja pada balok. N F w Di unduh dari : Bukupaket.com