KEGIATAN BELAJAR 9 MATERI POKOK : TEORI KINETIK GAS
A. URAIAN MATERI
A. Gas Ideal *-4@7-4 :0- C-:3 059-7>@0 01:3-: 3-> 501-8 -3-59-:-7-4 .1:?@70-=5<1=>-9--:3->501-8+:?@791:31?-4@5:C-<18-6-=58-4@=-5-: .1=57@? >1/-=- >-7>-9-
1. Pengertian Gas Ideal -8-9 .-. 5:5 :0- -7-: 919<18-6-=5 ?1;=5 75:1?57 3-> <-0- 3-> 501-8 '-0- 71:C-?--::C- >52-?>52-? 3-> 501-8 ?50-7 ?1=0-<-? 05 -8-9 7-:?1?-<5<-0->@4@7-9-=0-:?17-:-:?1=?1:?@3->0-<-?91958575 >52-? C-:3 91:017-?5 3-> 501-8 )1/-=- 957=;>7;<5> 3-> 501-8 91958575 >52-?>52-? >1.-3-5 .1=57@? - -> ?1=05=5 -?-> <-=?5718<-=?5718 0-8-9 6@98-4 C-:3 .1>-= 0-: ?50-7 ?1=6-05 5:?1=-7>5 -:?-=<-=?5718 3-> ?1=>1.@? . )1?5-< <-=?5718 >18-8@ .1=31=-7 71 >19.-=-:3 -=-4 / '-=?5718<-=?5718 3-> ?1=>1.-= 91=-?- 0-8-9 =@-:3 C-:3 >19<5? 0 !-=-7 -:?-=<-=?5718 6-@4 81.54 .1>-= 0-=5<-0- @7@=-: <-=?5718 1 +7@=-: <-=?5718 3-> 0-<-? 05-.-57-: 2 *50-7 ?1=0-<-? 3-C- -:?-=<-=?5718 71/@-85 657- ?1=6-05 ?@9.@7-: 3 @7@9 %1B?;: ?1:?-:3 31=-7 .1=8-7@ <-0- >5>?19 3-> ?1=>1.@?
y l A x
z
Gambar 7.1 Gerak arah partikel-partikel gas dalam ruang tertutup.
tekanan (p)
2. Persamaan Gas Ideal 0$'24 08-' F >1;=-:3 589@B-: '=-:/5> 918-7@7-: <1=/;.--:0-:<1:3-9-?-:@:?@791:31?-4@54@.@:3-:-:?-=-?17-:-: 0-:A;8@913->0-8-9>@-?@=@-:3?1=?@?@<<-0->@4@7;:>?-:@.@:3-: ?1=>1.@? 05@:37-< <-0- ?-4@: 0-: 0571:-8 01:3-: @7@9 ;C81 @7@9 ;C81 91:C-?-7-: .-4B- 657- 0-8-9 >@-?@ =@-:3 ?1=?@?@< ?1=0-<-? 3-> 501-8 C-:3 >@4@:C- 05@>-4-7-: ?1?-< ?17-:-: 3-> -7-: .1=.-:05:3 ?1=.-857 01:3-: A;8@91 3-> $1:@=@? ;C81 <1=>-9--: 71-0--: 3-> 4-:C- 05?1:?@7-: ;814 ?17-:-: 0-: A;8@91 3-> >145:33- <-0- 3-> -7-: .1=8-7@ <1=>-9--: 7;:>?-:-?-@
p2
100 K isotermal
p1 V1
V2
volume (V)
Gambar 7.2 Grafik hubungan tekanan (p) terhadap volume (V) pada suhu konstan.
F
"1?1=-:3-: ?17-:-:% 9 -?-@'- A;8@919 '23#.##/ 9 0571:-8 >1.-3-5 @7@9 ;C81 0-: .1=8-7@ @:?@7 4-9<5=>19@-3->01:3-:71=-<-?-:=1:0-4=-2574@.@:3-:-:?-=-?17-:-: 0-: A;8@91 3-> ?-9<-7 <-0- #.$#2 !57- ?17-:-: 05?@=@:7-: A;8@91 3-> -7-: :-57 )1.-857:C- 657- ?17-:-: 3-> 05:-577-: A;8@91 3-> -7-: 91:31/58 01:3-: >C-=-? >@4@ 3-> ?1?-<
119
)#2-'3F 0-:03'1)#8533#%F 918-7@7-: <1:3-9-?-:01:3-:<1=/;.--:?1:?-:34@.@:3-:-:?-=->@4@0-:A;8@91 <-0- ?17-:-: ?1?-< $1=17- 91:3-?-7-: 657- ?17-:-: 3-> 0-8-9 =@-:3 ?1=?@?@< 056-3- 7;:>?-: A;8@91 3-> >1.-:05:3 01:3-: >@4@ 9@?8-7:C- )1/-=- 9-?19-?5> 05:C-?-7-: 01:3-: <1=>-9--: 7;:>?-:-?-@
F
"1?1=-:3-: A;8@919 >@4@9@?8-7
Tokoh Joseph Louis Gay Lussac (1778–1850)
!57->@4@3->.5->-:C-05:C-?-7-:0-8-9 E>@4@9@?8-791:3 3@:-7-: >-?@-: "18A5: " 05:C-?-7-: 01:3-: <1=>-9--:
F
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
[email protected] 91:6-05
01:3-: -?-@
F
Sumber: Jendela Iptek 3, 1997
Ia dilahirkan di Prancis tahun 1778. Setahun setelah lulus dari politeknik Paris, ia ditawari pekerjaan oleh Claude-Louis Berthollet, kimiawan Prancis yang terkemuka. Berthollet memiliki laboratorium sendiri dan memimpin sekelompok ilmuwan muda di daerahnya. Gay Lussac mengadakan banyak riset bersama Berthollet dan Pierre Simon Laplace, dua ilmuwan yang dibiayai dan dilindungi oleh Napoleon Bonaparte. Gay-Lussac selamat dari arus revolusi Prancis, tetapi ayahnya tertangkap dan dipenjarakan. Pada 1802, ia mengulangi percobaan Alexander Cesar Charles. Ia menemukan fakta bahwa jika gas dipanaskan pada suhu tetap, volumenya akan bertambah sebanding dengan suhu mutlak. Jika suhunya dinaikkan dua kali lipat, volumenya akan meningkat dua kali. Hukum ini kali pertama ditemukan oleh Charles. Akan tetapi, karena Charles tidak mempublikasikannya, hukum tersebut kadang-kadang disebut hukum Charles, kadangkadang disebut Hukum Gay-Lussac.
"1?1=-:3-: 6@98-49;83-> ! 9;8"?1?-<-:@9@93-> !@98-49;83->91=@<-7-:<1=.-:05:3-:-:?-=-9->>-3->01:3-: 9->>-9;817@8=18-?52:C- )1/-=-9-?19-?5>6@98-49;83->0-<-? 05:C-?-7-: 01:3-: <1=>-9--: -?-@
F
120
!57- '23#.##/ 9 05>@.>?5?@>57-: 71 0-8-9 '23#.##/ 9 -7-: 05<1=;814 <1=>-9--: .1=57@?
F
-=5'23#.##/90-<-?05?1:?@7-:9->>-61:5> >@-?@3-> C-5?@
F
V (m3) p1 p2
p3
T (K)
)18-5: 0-<-? 05:C-?-7-: 0-8-9 6@98-4 9;8 <1=>-9--: @9@9 3-> 501-8 6@3- 0-<-? 05:C-?-7-: 0-8-9 6@98-4 <-=?5718 3-> ?1=>1.@? !@98-4<-=?57183->91=@<-7-:4->587-856@98-49;83->?1=>1.@?01:3-: .58-:3-: A;3=-0;
Gambar 7.3 Grafik hubungan volume (V) terhadap suhu mutlak (T) secara isobarik dengan p1 > p2 > p3. p (Pa) V1 V2
V3
T (K)
F
!57- '23#.##/ 9 05>@.>?5?@>57-: 71 0-8-9 '23#.##/ 9 -7-: 05<1=;814 <1=>-9--: .1=57@? !57- <1=>-9--: ?1=>1.@? 91:6-05 F "1?1=-:3-: 6@98-4 <-=?5718 3-> .58-:3-:A;3-0=; G 9;817@8 9;8 ?1?-<-:;8?D9-: G F ! "
Gambar 7.4 Grafik hubungan tekanan (p) terhadap suhu mutlak secara isokhorik dengan V 1 > V2 > V 3.
Ingatlah Pada suhu kamar dan tekanan tertentu, gas dapat memiliki sifat yang mendekati gas ideal.
Contoh 7.1 )-?@9;83->91:19<-?5A;8@919 0-:>@4@3-><-0->--??1=>1.@?-0-8-4 E *1:?@7-:8-4?17-:-:3->?1=>1.@? #7#$ 571?-4@5 9;8 ! 9;8" 9 E
" 1:3-:91:33@:-7-:<1=>-9--:05<1=;814 9 9;8 ! 79;8"
" G
% 9 !-05?17-:-:3->?1=>1.@?-0-8-4 G
% 9
Contoh 7.2 )-?@85?1=3->91958575?17-:-:-?9<-0-?19<1=-?@=F E1=-<-7-4?17-:-: 3->?1=>1.@?657-A;8@91:C-91:6-05 85?1=0-:?19<1=-?@=:C-91:6-05E #7#$ 571?-4@5 F " 85?1= "-?9 85?1=
121
1:3-:91:33@:-7-:'23#.##/905<1=;814 # -?9 #
" " -?9 !-05?17-:-:3->?1=>1.@?-0-8-4 -?9
Contoh 7.3 )1.@-4?-.@:3C-:3A;8@91:C-85?1=91958575
[email protected]:3C-:3919@:375:7-:@0-=718@-= 0-=5 ?-.@:3 $@8-9@8- >@4@ @0-=- 0-8-9 ?-.@:3 -0-8-4 E *-.@:3 05<-:->7-:45:33->@4@:C-91:6-05 E*1:?@7-:<1=.-:05:3-:-:?-=-9->>3->C-:3718@-=0-=5?-.@:30-:9->>--B-8:C- #7#$ *-.@:3.;/;=>145:33-?17-:-:?50-7
[email protected]7;:>?-:91>75<@:05<-:->7-:
"
" 01:3-:91:33@:-7-:<1=>-9--: -?-@
-8-94-85:5 7;:>?-:>145:33- !57-0595>-87-:9->>--B-83->0-:9->>--745=3->0-8-9?-.@:3-0-8-4 0-<-?05?@85>
" -?-@
" &8147-=1:-9->>-3->C-:3?1=>5>- .1=-=?5?18-4718@-=3->>1.-:C-7 C-5?@ F 1:3-:019575-:<1=.-:05:3-:-:?-=-9->>-3->C-:3718@-=0-:9->>-3->-B-8:C-0-8-4
Kata Kunci • gas ideal • jumlah mol
Tes Kompetensi Subbab
A
'2+#,#/-#)-#.$5,5-#4*)#/ )-?@9;83->91:19<-?5A;8@91
09 )@4@3-> <-0->--?5?@ E*1:?@7-:8-4?17-:-:3->?1=>1.@? )-?@ 85?1= 3-> <-0- ?17-:-: -?9;>21= 91958575 ?19<1=-?@= E1=-<-7-4?17-:-:3->?1=>1.@?657A;8@91:C-
[email protected]91:6-05 85?1=0-:?19<1=-?@= :C-91:6-05E
1=-<-7-4A;8@913=-93->4185@9<-0->@4@E 0-:?17-:-: 993 =73 79;8
)1.@-4?-:375@0-=-C-:3.1=5>5 73@0-=-<-0-?17-:-: -?905>59<-:05?19<-?C-:3.1=>@4@E'-0->--? 05<5:0-47-: 71 .1:3718 C-:3 .1=>@4@ E 7-?@< <1:3-9-:<-0-?-:375919.1.->7-:>16@98-4@0-=- !57-7-?@<.171=6-71?57-@0-=-0-8-9?-.@:39181.545 -?9?1:?@7-:9->>-@0-=-C-:305.1.->7-:
B. Prinsip Ekuipartisi Energi '-0-.-4->-:>1.18@9:C-?18-405618->7-:.-4B->1?5-<<-=?57183-> 501-8>18-8@.1=31=-7 >145:33- 91:34->587-: 1:1=35 75:1?57 &8147-=1:>52-? 3-> 501-8 05?5:6-@ >1/-=- 71>18@=@4-: 1:1=35 75:1?57 >1?5-< <-=?5718 :C- 91=@<-7-: 1:1=35 75:1?57 =-?-=-?- -8 ?1=>1.@? 91:C1.-.7-: ?59.@8:C- <=5:>5< 17@5<-=?5>5 1:1=35
122
y
1. Tekanan Gas dalam Ruang Tertutup
dinding A
z
m0
vx
dinding B
x
Gambar 7.5 Tanda panah menyatakan momentum sebuah molekul setelah menumbuk dinding.
'1=4-?57-: #.$#2 )@-?@ 3-> 501-8 ?1=7@=@:3 0-8-9 >1.@-4 7@.@> C-:3 91958575 <-:6-:3 =@>@7 )1.@-4 <-=?5718 0-=5 3-> 501-8 ?1=>1.@? .1=31=-7 0-8-9 -=-4 >@9.@-# 01:3-: 71/1<-?-: " # 0-: 918-7@7-: 31=-7 .;8-7.-857 0-=5 05:05:3 71 05:05:3 719@05-: 719.-858-357105:05:3!-=-7C-:305?19<@4<-=?5718?1=>1.@?-0-8-4 "1/1<-?-:>18-9-.1=31=-7>18-8@>-9-7-=1:-?@9.@7-:C-:3?1=6-05 -:?-=<-=?5718 0-: 05:05:3 05->@9>57-: >1.-3-5 ?@9.@7-: 81:?5:3 >19
<@=:- ,-7?@ ?19<@4 <-0- 31=-7 .;8-7.-857 ?1=>1.@? -0-8-4 " # >10-:37-: .-:C-7:C- ?@9.@7-: <1= >-?@-: B-7?@ C-:3 05.@-? ;814 " <-=?5718 0-: 05:05:3 -0-8-4 # 0-<@: <
[email protected]: 9;91:?@9 C-:3 05-8-95 9;817@8 0-<-? 05?@85>7-: >1.-3-5 .1=57@? <
[email protected]:9;91:?@99;91:?@9-745=F9;91:?@9-B-8 1 F<6#F<6# 1 F <6#
Tantangan untuk Anda
F
*-:0- :13-?52 <-0- 9;91:?@9 -745= <-=?5718 91:@:6@77-: -=-4 31=-7<-=?5718>1?18-4?@9.@7-:C-:3.1=8-B-:-:-=-401:3-:-=-431=-7 -B-8:C- -=5 <1=>-9--: <
[email protected]: 9;91:?@9 ?1=>1.@? 0-<-? 05/-=5 3-C- C-:3 .171=6- <-0- <-=?5718 C-5?@ <
[email protected]: 9;91:?@9 C-:3 05<5:0-47-: ;814 <-=?5718 71 05:05:3 <1= >-?@-: B-7?@ 1 < 6 # "# < 6 # F '-0- 71:C-?--::C- <-=?5718 C-:3 91:@9.@7 05:05:3 ?50-7 4-:C>-?@ <-=?5718 ?1?-<5 >16@98-4 <-=?5718 &814 7-=1:- 5?@ 3-C- C-:3 05?1=59- 05:05:3 -75.-? ?@9.@7-: <-=?5718 -0-8-4
< 6 # #
Sumber: Fundamentals of Physics, 2001
Pernahkah Anda minum minuman bersoda? Ketika Anda membuka tutup botolnya, akan terbentuk kabut tipis di sekitar tutup botol tersebut. Mengapa hal ini terjadi?
F
*-:0-:13-?52<-0-'23#.##/9 4-:C-91:@:6@77-:-=-43-C-:C>-6-!57-:0-4-:C-5:35:91:31?-4@5.1>-=:C-?-:0-:13-?52?1=>1.@?0-<-? 05458-:37-: +:?@7 91:31?-4@5 ?17-:-: C-:3 05-8-95 05:05:3 ?-.@:3 <1=>-9--: ?1=>1.@? 05.-35 01:3-: 8@-> <1=9@7--: 7@.@> -8 ?1=>1.@? 057-=1:-7-: ?17-:-: 91=@<-7-: <
[email protected]: 9;91:?@9 C-:3 05<5:0-47-: ;814>16@98-4<-=?57187105:05:3<1=>-?@-:B-7?@@:?@7>1?5-<>-?@-:8@-> < 6 # 1# # &814 7-=1:- A;8@91 -7-: 050-<-?7-: <1=>-9--: < 6 # F # -0-8-4 ?17-:-: <-0- 05:05:3 @:?@7 >@9.@-# 1:3-: /-=- C-:3 >-9- ?17-:-: 3-> <-0- 05:05:3 ?13-7 C-:3 >1-=-4 >@9.@-$ 0-: >@9.@-% 05=@9@>7-: >1.-3-5 .1=57@?
1#
123
< 6 $ < 6 % 0-:1D +:?@7 91:31?-4@5 =1>@8?-: 0-=5 ?17-:-: 4-=@> 05/-=5 ?1=81.54 0-4@8@ =1>@8?-: 71/1<-?-::C- $1:@=@? 7-50-4 A17?;= .1>-= =1>@8?-: 71/1<-?-: -0-8-4 >1.-3-5 .1=57@? " "# "$ "% 01:3-:"# "$ "% 9-7" "# "# "
1:3-: 019575-: <1=>-9--: ?17-:-: 3-> <-0- =@-:3 ?1=?@?@< -0-8-4 < " F
"1?1=-:3-: ?17-:-:3->% 9 -?-@'- < 9->>- <-=?5718 73 6@98-4 <-=?5718 " 71/1<-?-: 31=-7 <-=?5718 9 > A;8@913->9 '1=>-9--:?17-:-:3->0-8-9=@-:3?1=?@?@<05-?->0-<-?05:C-?-7-: 1$
0-8-9 .1:?@7 1:1=35 75:1?57 =-?-=-?- 0-=5 <-=?5718 3-> C-5?@ E < v < v !-05
F
"1?1=-:3-: 1:1=35 75:1?57 =-?-=-?- >-?@ <-=?5718 3-> 6;@81
Contoh 7.4 !57-71/1<-?-:<-=?57183->91:6-050@-7-8571/1<-?-:>19@8-?1:?@7-:8-4.1>-=:C?17-:-:C-:3054->587-: #7#$ " @.@:3-:?17-:-:?1=4-0-<718-6@-:"-0-8-4
&8147-=1:-:58-5 7;:>?-::58-5>1.-:05:301:3-: " >145:33 " " " " !-05?17-:-:3->91:6-0519<-?7-85?17-:-:>19@8-
Contoh 7.5 )1.@-4?-.@:301:3-:A;8@91 9 91:3-:0@:3 9;8185@9<-0->@4@ E 1:3-:91:3-:33-<185@9>1.-3-53->501-8?1:?@7-: - 1:1=3575:1?573->185@9 . 1:1=3575:1?57=-?-=-?->1?5-<9;83->185@9?1=>1.@? #7#$ - 571?-4@5 A;8@91?-.@:3 9 9;8 "
124
Pembahasan Soal Sebuah ban sepeda memiliki volume 100 cm3. Tekanan awal dalam ban sepeda adalah 0,5 atm. Ban tersebut dipompa dengan suatu pompa yang volumenya 50 cm3. Jika diasumsikan temperatur tidak berubah, tekanan dalam ban sepeda setelah dipompa 4 kali adalah .... a. 0,1 atm d. 4,5 atm b. 2,5 atm e. 5,0 atm c. 4,0 atm Soal Tes ITB Tahun 1975 Pembahasan: Volume ban = V1 = 100 cm2 p1 = 0,5 atm V2 = 4 × 50 cm3 = 200 cm3 p2 = 76 cmHg = 1 atm Setelah pemompaan ban selesai maka akan berlaku: pban Vban = p1V1 + p2V2 pban
= =
p1V1 + p2V2 Vban 0,5 atm100 cm3 + 1atm200 cm3 100 cm3
= 2,5 atm. Jadi, tekanan ban setelah dipompa sebesar 2,5 atm. Jawaban: b
.
1:3-:91:33@:-7-:'23#.##/9 05<1=;814
-?-@
9;8 ! 9;8"
" ! !-051:1=3575:1?57?;?-83->-0-8-4 6;@81 !@98-49;817@83->-0-8-4 9;8 G 9;817@8 9;8 G :1=3575:1?57=-?-=-?->1?5-<9;817@8-0-8-4 ! 6;@81 +:?@77->@>A;8@913->?50-705<1=45?@:37-:
2. Energi Kinetik dan Energi Dalam Gas -8-9?5:6-@-:957=;>7;<5><-=?5718<-=?57180-8-93->>18-8@.1=31=-7 >145:33-<-=?5718<-=?5718?1=>1.@?919585751:1=3575:1?57'1=>-9--:1:1=35 75:1?57 <-0- <-=?5718 3-> 501-8 0-<-? 05?@=@:7-: >1.-3-5 .1=57@? "
)@.>?5?@>5 0-=5 710@- <1=>-9--: ?1=>1.@? -7-: 91:34->587-: <1= >-9--: .1=57@? "
"
"
"
F $@:/@8:C- 2-7?;= <1:3-85 <-0- '23#.##/ 9 05>1.-.7-: ;814 <1=>-9--: =-?-=-?- 7;9<;:1: A17?;= 71/1<-?-: " "# "$ "% 01:3-:"#"$"% " "#
&8147-=1:-5?@2-7?;=<1:3-85 .1=7-5?-:01:3-:01=-6-?71.1.->-: 31=-7 <-=?5718 C-:3 .1=?=-:>8->5 71 -=-4 >@9.@-# $ 0-: % '23#.##/ 9 .1=8-7@@:?@73->9;:;-?;957C-:3.1=?17-:-:=1:0-4;:?;4 3-> 9;:;-?;957 -0-8-4 4185@9 1 :1;: %1 0-: -=3;: = +:?@73->05-?;957>1<1=?5 & 0-:% <-0->@4@0-:?17-:-:
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125
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>@9.@-% 91:34->587-: 1:1=35 75:1?57 =-?-=-?- C-5?@ G &814 7-=1:- 5?@ <-0- >@4@ >10-:3 <-=?5718 3-> 05-?;957 918-7@7-: 31=-7 =;?->5 0-: ?=-:>8->5 >145:33- 1:1=35 75:1?57:C- 91:6-05
7 F '-0->@4@0-:?17-:-:?5:335<-=?57183->05-?;9570-<-?918-7@7-: ?53- 31=-7-: C-5?@ .1=?=-:>8->5 .1=;?->5 0-: .1=A5.=->5 1=-7 A5.=->5 91958575 0@- 61:5> 7;:>?=5.@>5 1:1=35 C-5?@ 1:1=35 75:1?57 0-: 1:1=35 <;?1:>5-8 18->?57 1=-7 A5.=->5 ?1=>1.@? 91:34->587-: 0@- 01=-6-? 71.1.->-: 1:3-: 019575-: 1:1=35 75:1?57 3-> 05-?;957 <-0- >@4@ 0-: ?17-:-: ?5:335 91:6-05
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1:3-: 019575-: .1>-=:C- 1:1=35 75:1?57 <-=?5718 .1=3-:?@:3 <-0>@4@0-:?17-:-:C-:3-7-:9191:3-=@4531=-7-:0-=5<-=?5718?1=>1.@? '-0->1?5-<31=-7-:?=-:>8->5=;?->50-:A5.=->5>1?5-<<-=?571891958575 /-=- @:?@7 91:C59<-: 1:1=35:C- '1:5:6-@-: 1:1=35 75:1?57 >1<1=?5 5:5 05:-9-7-: ! '=5:>5<5:591:C-?-7-:.-4B-@:?@7>@-?@>5>?19<-=?57183-><-0>@4@ 9@?8-7 01:3-: >1?5-< <-=?5718:C- 91958575 01=-6-? 71.1.->-: 1:1=35 75:1?57 =-?-=-?- >1?5-< <-=?5718 7 -0-8-4
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Gambar 7.6 Gerak molekul diatomik: (a) gerak translasi dari pusat massa; (b) gerak rotasi terhadap sumbu kartesius; dan (c) gerak vibrasi sepanjang sumbu molekul.
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• Untuk gas monoatomik, f = 3. • Untuk gas diatomik suhu sedang, f = 5. • Untuk gas diatomik suhu tinggi, f = 7.
126
Kata Kunci • • • •
ekuipartisi energi energi dalam gas energi kinetik gas tekanan gas
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C. Kecepatan Efektif Partikel Gas !57-0-8-9>@-?@=@-:3?1=?@?@<?1=0-<-?>1.-:C-79;817@8C-:3 .1=31=-7 01:3-: 71/1<-?-: " 9;817@8 C-:3 .1=31=-7 01:3-: 71/1 <-?-:" 0-:>1?1=@>:C-=-?-=-?-7@-0=-?71/1<-?-:<-=?57183->" 0-<-? 05?@85> >1.-3-5 .1=57@? "
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Informasi untuk Anda Energi Matahari berasal dari reaksi fusi nuklir yang berasal dari penggabungan 2 buah proton. Sebenarnya, proton memiliki gaya tolak menolak dengan proton lainnya karena muatannya sejenis. Selain itu, proton tidak memiliki energi kinetik yang cukup besar untuk mengatasi gaya tolak-menolak tersebut. Akan tetapi, ada sebagian proton yang memiliki kecepatan tinggi sehingga memiliki energi kinetik yang cukup besar. Oleh karena itu, Matahari masih bersinar.
Information for You The suns energy is supplied by nuclear fusion process that starts with the merging of two protons. However, protons have a motion to repel each other because of their electrical charges and protons of average speed do not have enough kinetic energy to overcome the repulsion. Very fast protons with speed can do so, however and for that reason the sun can shine. Sumber: Fundamentals of Physics, 2001
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Tes Kompetensi Subbab
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