Proses Adiabatik Aplikasi Hukum I Termodinamika pada Proses-Proses Termodinamika

Mudah dan Aktif Belajar Fisika untuk Kelas XI 188 ?CD2?D2 2A=246 C642B2 D6B:D:C 52A2D 5:9:DE?8 C6CE2: 56?82? A6B C222? 36B:ED M 2C?2D: A M 2C5:2D: A - 6?E?;E2??:=2:?CD2?D22A=246E?DE3636B2A282C A252D62?2?2D52?CE9EL ,E9E882C?:DB86?36B2D=6E=8 =5:?2:2?52B:L 6?;25: L 6=2=E:ABC6C:C32B::DE?86?2:2?6?6B8:52=252?EC292H2?85:=2E2?=6982C 7 2C A25262522?:?:52A2D5:8=?82?C63282:82C5:2D:CE9EC652?8C69:?882 2A2C:D2CA2?2C=2B82CA252F=E6D6D2A52?A252D62?2?D6D2A252=29 1 = = , = = E=29=82C252=29C2DE2?2CC2?H292BEC5:E32952=28B2 = 8 = = :6D29E: = 1 = , = O F = =P A = =P O P OP P Contoh 8.7 Tantangan untuk Anda Anda pasti pernah mendengar istilah mesin 4 tak dan mesin 2 tak. Selidikilah dan diskusikanlah, apa perbedaan di antara keduanya? Mengapa mesin 2 tak memiliki akselerasi lebih cepat daripada mesin 4 tak? ,6B2?8 :=EG2? B2?4:C 204 O 6?H2D22? 329G2 C6E2 A6B86B22? 36B9E3E?82? 56?82? 2=B :C2=?H2 86B22? 86B22?H2?8D6B;25:52=2A6B2=2D2?62?:C6A6BD:6C:?5:6C6=6C:? 2=B 56 2B?D 6?H:B2D2? 329G2 52A2D 5:4:AD22? C63E29 6C:? :562= H2?8 C6=EBE9 6?6B8:?H2 5:8E?22? 6?;25: EC292 2E? A252 6?H2D22??H2 92= D6BC63ED CE=:D 5:4:AD22? 02=2EAE? 56::2? D6B: 2B?D 2C:9 D6D2A 5:A22: 9:?882 C22D :?: ,642B2 D6B:D:C 6C:? 2B?D 6?E?;E2? 3636B2A2 72DB H2?8 36BA6?82BE9A25267:C:6?C:C63E296C:?6?8E329EC2926?;25:2=B 52A2D 5:=2E2? C642B2 D6BEC 6?6BEC 2? D6D2A: 6?8E329 2=B 6?;25: EC292 D:52 56::2? 92BEC 5:EC2922? C6;E=29 82C 632=: 662522??H2C6E=2282B82CD6BC63ED52A2D6=2E2?EC292632=: BC6C C6A6BD: :?: 5:C63ED .0. 252D29E?2B?D6?;6=2C2?C63E29C:=ECH2?8D6B5:B:2D2C 6A2D ABC6C 6B92D:2? .2 52? .2 p V A Q 1 T 1 B C T 2 Q 2 D W Gambar 8.10 Satu siklus suatu mesin Carnot menggunakan suatu gas ideal sebagai fluida kerja. Grafik AB dan CD menampilkan proses isotermal, grafik BC dan DA menampilkan proses adiabatik. - -6D2A2?2A=246 2C 2C -6BD6?DEA252-62?2?2D 52?,E9EL 3 +++ 6=:E6 B8?B + :DB86? C:86? 2B3? ?C:52 Sumber: Fundamental of Physics, 2001 Termodinamika 189 BC6C52B:6252=29ABC6C6CA2?C:2D2EABC6CA6?8632?82? :CD6B2= A252 CE9E 252 ABC6C :?: 82C 6?H6B2A 2=B 52B: B6C6BF:B 36BCE9E D:?88: 52? 6=2E2? EC292 BC6C 52B: 6 252=29ABC6CA6?8632?82?25:232D:,6=22ABC6CCE9E82CDEBE? 52B: 6?;25: C23:= 6=2E2? EC292 BC6C 52B: 6 252=29ABC6CA62A2D2?:CD6B2=A252CE9E 2=2ABC6C:?:82C 6=6A2C 2=B 6 B6C6BF:B 36BCE9E B6?529 52? 6=2E2? EC292 BC6C 29:B 52B: 6 252=29 ABC6C A62A2D2? 25:232D: ,E9E ?2: 52B: 6 C23:= 6=2E2? EC292 ,:=EC2B?D252=2952C2B52B:6C:?5:6C6=H2:DE6C:?H2?8A2=:?8 :562=H2?8C6=2?;ED?H25:C63ED6C:?2B?D,6=22ABC6CC:=EC2B?D 36B=2?8CE?8 82C 6?6B:2 2=B 52B: B6C6BF:B 36BCE9E D:?88: 52? 6=6A2C 2=B 6 B6C6BF:B 36BCE9E B6?529 .C292 H2?8 5:=2E2? =69 82C C6CE2: 56?82? EE -6B5:?2:2 252=29 2D2E O O O 6D6B2?82? 2=B H2?8 5:C6B2A 52B: B6C6BF:B H2?8 36BCE9E D:?88: 2=B H2?8 5:=6A2C 6 B6C6BF:B H2?8 36BCE9E B6?529

3. Efisiensi Mesin

6B92D:2?.2 232BD6BC63ED6?E?;E2?C:=EC2=B 5: 52=2 C63E29 6C:? 6B32?5:?82? 2?D2B2 36C2B?H2 EC292 H2?8 52A2D 5:=2E2? =69 C:CD6 D6B9252A 2=B H2?8 5:C6B2A 52A2D 6?6?DE2?67:C:6?C:CE2DE6C:?,642B22D62D:C67:C:6?C:6C:?52A2D 5:DE=:C2? C63282: 36B:ED P O

a. Mesin Carnot

7:C:6?C: 6C:? 2B?D 5:A6B=69 56?82? 42B2 6?882?D: EC292 56?82? 23. 9 C69:?882 23. 9 6?;25: P 2D2E P O -6=29 5:3292C 329G2 E?DE CE2DE 82C :562= 6?6B8: 52=2 C632?5:?8 56?82? CE9E ED=2 C69:?882 E?DE 6C:? 2B?D 23. 9 52A2D 5:DE=:C C63282: 36B:ED P O 6?882?D:2? 36C2B2? 2=B 6?;25: CE9E ED=2 52=2 6?6?DE2? 67:C:6?C: C63E29 6C:? 36B52C2B2? A252 6?6B8: 52=2 C632?5:?8 56?82? CE9E 6=F:? 6?E?;E2? 329G2 O 6D6B2?82? CE9E B6C6BF:B D:?88: CE9E B6C6BF:B B6?529 Gambar 8.11 Siklus mesin ideal Q 1 dan suhu fungsi reservoir diubah seluruhnya menjadi usaha W dengan efisiensi 100. T 1 Q 1 W = Q 1 Q 2 = 0 Kata Kunci • efisiensi mesin Gambar 8.12 Perubahan kalor menjadi kerja: Q 1 = kalor masuk; Q 2 = kalor dilepaskan; W = usaha yang dilakukan; T 1 = suhu reservoir tinggi; dan T 2 = suhu reservoir rendah. T 1 Q 1 Q 2 W T 2