e.Bal ok Ter usan/Bal ok Ger ber Bal okGer beradal ahsuat ubal okyangdit umpu ol ehdar i2( dua)t umpuanat au l ebi h.
A
B
C
Penyel esai an per hi t ungan unt uk bal ok ger beri nisebenarnya dengan st at i st ak t ent u, di manaol eht uan Ger berdapatdi sesuai kandenganst at i st er t ent u,dengancar ame memb mberiat au mel et akansendidi ant ara2( dua)t umpuant er sebut .
Mi sal nyase buah bal okt umpuan di manase ndi nyat er l e t ak pada A –B at au B –C . Dal am hali niadaat ur annyaunt ukme menent ukan j uml ahsendi ,denganm me engg unakanr umus:
Juml ahs e ndi(S)=n–2
di mana n=j uml ml aht ump mpuan
a) At au S A
b) S B
C
Pr i nsi pperhi t unganunt ukbal okger ber: 1. Deng anpr i nsi pbal okt umpuans ede r hana 2. Denganpr i nsi pove rst eakat aubal okt umpuanmenj or ok
Gamb mbarbal okger ber: 1. Dengan3( t i ga)t umpuan
S A
R A
B
C
RS
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RB
RC
S A
B
C
RS
R A
RB
RS
RC
2.De ngan4( e mpat )t umpuan S1 A
S2
B
C
RS1
R A
RS2
RB
RC
S1 A
R A
D
RD
S2 B C
RS1
D
RS2
RD
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RB
Rc
CONTOH SOAL: 1.Hi t ungr eaksi-r eaksiyangt er j adidangambar kanbi dangD danM ! P1 =4t on S D B
A 2m
( I )
R A
2m
P2 =3t on E
1m 1m
C 3m
P1
RS
P2
( I I ) RB
RC
Bagi an( I ): on R 4=2t A =RS =½ P 1=½ .
2, 75 2
on m MD =R 2=2.2=4t A.
+ A
D
+ E
B
C
Bagi an( I I ):
0 , 2 5 2
Σ
Σ
MC=0 -RS .5+RB .4–P2 .3=0 -2.5+ 4.RB –3. 3=0 75t on RB =19/4=4, V=0 -RS +RB –P2 +RC =0 25t on RC =0,
-
2
MB
A
D
B
E
C
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Gay aDi ag onal on D A =2t
ME
on DD =2–4=-2t 75t on DB =-2+4, 75=2, 25t on DE =2, 75–3=0,
MD
Mome n M A =MC =0 on MD =4t
on m MB =R 5–P1. 3=2. 5–4 . 3=-2t A. 75t on m ME =R 6–P1. 4+RB. 1=2. 6–4. 4+4, 75. 1= 0. A.
2.Hi t ungr eaksi-r eaksiyangt er j adidangambar kanbi dangD danM ! S A
q=2t /m
B 5m
C 2m
6m ( I ) RS
( I I )
R A
RC
RS
RB
Bagi an( I ): 10
on Rc=RS =½ Q=½ . ( 2. 6)=6t on m Mmax =1/8. q . L2 =1/8. 2. 62 =9t +
Bagi an ( I I )overst eak : Σ
MB =0 R .5–Q. ( 1/2. 7–2)+RS. 2=0 A
1, 8 A
B x
-
C 6
8, 2
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R .5–( 2. 7) . ( 1, 5)+ 12=0 A 8t on R /5=1, A =9 Σ V=0 -RS +R Q =0 A +RB 2t on RB =18,
MB
A
Mmas=R x–( q. x) . 1/2. x=R x–½ . q. x2 A. A.
B
C
M xma x M xma x
Me nc a r ix: x = 5–x di dapatni l ax=0, 9m dar it i t i kA 1, 8 8, 2 2 81t on m maka Mmas=R x–½ . q. x2=1, 8. ( 0, 9)–½ . 2. ( 0, 9) = 0, A.
Gay aDi ag onal , 8t on D A =1
2t on DB =1, 8–( 2. 5)=-8, on =-8, 2+18, 2=10t on DC =10–( 2. 8)=6t Mome n M A =MC =0 on m MB =R 5–Q. 2, 5=1, 8. 5–( 2. 5) . 2, 5= -16t A.
SOALLATI HAN : Hi t ungr eaksi-r eaksiyangt er j adidangambar kanbi dangN,D danM ! 1.
2t on
1t on
3t on S
A
D 2m
2.
E 3m
B
F
1m 2m 2m
P1=2t on
C 3m
P2=3t on S
A
B 5m
1m
45° D
2m
C 2m
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q1 =2t /m 3.
q2 =3t /m
3t on
A
D 2m
4t on
E 4m
5m
B
S 2m
F G 3m 1m
3t on
H 3m
C 1m
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