3U]\NáDG8NáDGEHONRZ\]áR*RQ\
3ROHFHQLH Z\]QDF]\ü UHDNFMH SRGSRURZH GOD SRQL*V]HM EHONL REFL*RQHM VLá VNXSLRQ
P i
REFL*HQLHPFLJá\P
q(x)
RQDW *HQLX]PLHQLDMF\PVL OLQLRZR
Oznaczamy podpory literami A, B i C
QDWRPLDVWSRáF]HQLDSU]HJXERZHF\IUDPL
1 i 2.
8ZDOQLDP\XNáDGRGZL ]yZL]DVW SXMHP\SRGSRU\UHDNFMDPL
W utwierdzeniu w punkcie A
G]LDáDM QDVW SXMFH UHDNFMH PRPHQW
M
A
RUD] VNáDGRZD
pionowa V
A
i pozioma H
A
NWyUHVRGVLHELHQLH]DOH*QH:SXQNFLH
B
Z\VW SXMHUHDNFMD
R
B
o
P = 3 ql
6 q
.
= 30
o
l
l
3 l
2 l
2 l
= 60
o
6 q
P = 3 ql
.
= 30
o
l
l
3 l
2 l
2 l
= 60
o
A
B
C
2
1
C
R
C
90
o
.
= 30
o
= 60
o
= 90
o
í.
60
o
II
6 q
P = 3 ql
l
l
3 l
2 l
2 l
= 60
o
A
B
C
2
1
= 60
o
H
A
M
A
V
A
R
B
R
C
I
x
y
2
SLRQRZHM OLQLL G]LDáDQLD QDWRPLDVW Z SXQNFLH
C reakcja R
C
G]LDáDMFD Z]GáX* SURVWHM
QDFK\ORQHMGRSR]LRPXSRGNWHP
= 60
o
.
5R]ZL]DQLH ]DGDQLD UR]SRF]QLHP\ RG ]DSLVDQLD UyZQDQLD PRPHQWyZ Z]JO GHP SXQNWX
1
GOD F] FL
I
XNáDGX : UyZQDQLX W\P Z\VWSL GZLH QLHZLDGRPH
M
A
i V
A
, natomiast
SR]RVWDáH VLá\
V
1
, H
1
i H
A
PDM OLQLH G]LDáDQLD SU]HFKRG]FH SU]H] SXQNW
1
D ZL F PRPHQW\
W\FKVLáZ]JO GHPSXQNWX
1
VUyZQH]HUX
∑
=
i
I
i1
M
0 :
í
M
A
í
V
A
Â
l = 0 ( * )
=DSLV]HP\ QDVW SQH UyZQDQLH PRPHQWyZ Z]JO GHP SXQNWX
2
GOD F] FL
II
XNáDGX Z
NWyU\P Z\VWSL WH VDPH QLHZLDGRPH : SXQNFLH
2
ZDUWRü QDW *HQLD REFL*HQLD FLJáHJR
wynosi 4 q.
)LJXUD SRG Z\NUHVHP UR]NáDGX QDW *HQLD REFL*HQLD FLJáHJR PL G]\ SU]HJXEDPL
1 i 2 jest
WUDSH]HP : FHOX XQLNQL FLD NRQLHF]QRFL Z\]QDF]DQLD OLQLL G]LDáDQLD Z\SDGNRZHM WHJR
REFL*HQLD SRáR*HQLD URGND FL *NRFL WUDSH]X SRG]LHOLP\ REFL*HQLH FLJáH G]LDáDMFH QD
W F] ü XNáDGX ]JRGQLH ] SRQL*V]\P U\VXQNLHP :\]QDF]DP\ ZDUWRFL Z\SDGNRZ\FK MDNR
SRODILJXUSRGZ\NUHVDPLUR]NáDGXQDW *HQLDREFL*HQLDFLJáHJR
q
W
II
p
4
=
Â
2 l = 8 ql,
2
1
=
II
t
W
Â
q
Â
l = 2 ql
I
l
A
1
H
A
M
A
V
A
H
1
V
1
II
t
W
II
p
W
1
2
1
2
l
l
l
3
4
3
2
l
4 q
2 q
2 l
II
p
W
II
t
W
II
2 l
l
A
1
H
A
M
A
V
A
H
2
V
2
2
l
l
l
3
4
3
2
l
4 q
2
6 q
l + 3 l = 4 l
2 l
1
3
5yZQDQLHPRPHQWyZZ]JO GHPSXQNWX
2
GODF] FL
II
XNáDGXPDSRVWDü
∑
=
i
II
i2
M
0 :
II
p
W
Â
l +
II
t
W
Â
3
4
l
í
M
A
í
V
A
Â
l = 0 ( ** )
: UyZQDQLX W\P QLH Z\VW SXM QLHZLDGRPH
H
A
, V
2
i H
2
/LQLH G]LDáDQLD W\FK VLá SU]HFKRG]
SU]H] SXQNW ZL F LFK PRPHQW\ Z]JO GHP SXQNWX V UyZQH ]HUX 3R SRGVWDZLHQLX GR
UyZQDQLD ZDUWRFLZ\SDGNRZ\FK
II
p
W i
II
t
W
UR]ZL]XMHP\XNáDGUyZQD
í
M
A
í
V
A
Â
l = 0 ( * )
í
M
A
í
V
A
Â
l +
3
32
Â
ql
2
= 0 ( ** )
=UR]ZL]DQLDXNáDGXUyZQDRWU]\PXMHP\
M
A
=
í
3
16
ql
2
, V
A
=
3
16
ql.
:\]QDF]RQHUHDNFMHQDVFKHPDFLHXNáDGXR]QDF]RQHVNRORUHPF]DUQ\P
3R]RVWDáHUyZQDQLDUyZQRZDJL]DSLV]HP\GODFDáHJRXNáDGX
3U]HG ]DSLVDQLHP UyZQD UyZQRZDJL Z\]QDF]\P\ Z\SDGNRZ REFL*HQLD FLJáHJR RUD]
VNáDGRZSLRQRZLSR]LRPVLá\VNXSLRQHMSU]\áR*RQHMGRSUDZHJRNRFDXNáDGX
:UyZQDQLXVXP\PRPHQWyZZ]JO GHPSXQNWX
C
Z\VWSLW\ONRMHGQDQLHZLDGRPD
R
B
JG\*
OLQLHG]LDáDQLDUHDNFML
H
A
i R
C
SU]HFKRG]SU]H]SXQNW
C
DZL FPRPHQW\Z\PLHQLRQ\FKVLá
Z]JO GHPWHJRSXQNWXVUyZQH]HUX
0
=
∑
i
iC
M
:
í
M
A
í
V
A
Â
l
í
R
B
Â
l
í
P
y
Â
l + W
Â
l + l ) = 0
⇒
R
B
=
3
37
ql
=DSLV]HP\WHUD]UyZQDQLHVXP\U]XWyZVLáQDRSLRQRZGODFDáHJRXNáDGX
6 q
P = 3 ql
l
l
3 l
2 l
2 l
= 60
o
A
B
C
2
1
= 60
o
H
A
M
A
=
í
3
16
ql
2
V
A
=
3
16
ql
R
B
R
C
P
x
= 3 ql
ÂFRV
=
2
3
ql
l
l
3 l
2 l
2 l
A
B
C
2
1
= 60
o
H
A
M
A
=
í
3
16
ql
2
V
A
=
3
16
ql
R
B
R
C
P
y
= 3 ql
ÂVLQ
=
2
3
ql
W =
2
1
Â
q
Â
l + l + 3 l ) = 18 ql
4
∑
=
i
iy
P
0 : V
A
+ R
B
+ R
C
ÂVLQ
í
W
í
P
y
= 0
⇒
R
C
=
9
3
11
ql
6XPD U]XWyZ VLá QD R SR]LRP GOD FDáHJR XNáDGX XPR*OLZL Z\]QDF]HQLH RVWDWQLHM
niewiadomej H
A
.
0
=
∑
i
ix
P
: H
A
í
R
C
ÂFRV
í
P
x
= 0
⇒
H
A
=
9
3
10
ql.
6SUDZG]LP\ SRSUDZQRü Z\NRQDQ\FK REOLF]H ]DSLVXMF UyZQDQLH UyZQRZDJL ZF]HQLHM
niewykorzystane.
∑
=
i
iA
M
0 :
í
M
A
í
W
Â
l
í
P
y
Â
l + R
B
Â
l + R
C
ÂVLQ
Â
l =
=
í
(
í
3
16
Â
ql
2
)
í
ql
Â
l
í
2
3
ql
Â
l +
3
37
ql
Â
l +
9
3
11
ql
Â
2
3
Â
l =
= ql
2
(
3
16
íí
2
27
+
3
148
+
6
77
)
= 0
5yZQDQLHVSHáQLRQHMHVWWR*VDPRFLRZR
3U]HGVWDZLP\RWU]\PDQHZ\QLNLZSRVWDFLOLF]EG]LHVL WQ\FK
M
A
=
í
3
16
ql
2
=
í
ql
2
, V
A
=
3
16
ql = 5,33 ql, H
A
=
9
3
10
ql = 1,92 ql
R
B
=
3
37
ql = 12,33 ql, R
C
=
9
3
11
ql = 2,12 ql
=DSLV]HP\MHV]F]HUD]UyZQDQLHPRPHQWyZZ]JO GHPSXQNWX
A
GODFDáHJRXNáDGX
∑
=
i
iA
M
0 :
í
M
A
í
W
Â
l
í
P
y
Â
l + R
B
Â
l + R
C
ÂVLQ
Â
l =
=
í
(
í
ql
2
)
í
ql
Â
l
í
ql
Â
l + 12,33 ql
Â
l + 2,12 ql
Â
0,866
Â
l =
= 0,0014 ql
2
§
2WU]\PDQ\ Z\QLN QLH ZLDGF]\ R SRSHáQLHQLX Eá GX MHVW QDWRPLDVW NRQVHNZHQFM
]DRNUJOHQLDZDUWRFLUHDNFML
W tym samym zadaniu wyznaczymy reakcje
EH] NRQLHF]QRFL UR]ZL]\ZDQLD XNáDGX GZX
UyZQD ] GZLHPD QLHZLDGRP\PL 5R]ZD*DQ\ XNáDG EHONRZ\ SRG]LHOLP\ QD SRMHG\QF]H
EHONL]ZDQHSRGXNáDGDPL
l
l
3 l
2 l
2 l
P
x
=
2
3
ql
A
B
C
2
1
= 60
o
H
A
=
9
3
10
ql
M
A
=
í
3
16
ql
2
V
A
=
3
16
ql
R
B
=
3
37
ql
R
C
=
9
3
11
ql
P
y
=
2
3
ql
W =
2
1
Â
q
Â
l + l + 3 l ) = 18 ql
5
3RQL*V]\U\VXQHNSU]HGVWDZLDVFKHPDWSUDF\XNáDGXEHONRZHJR
5R]ZL]\ZDQLH]DGDQLDUR]SRF]\QDP\RG F] FL
II ), która w punkcie 1 i 2
SRáF]RQD MHVW
SU]HJXERZR]VVLHGQLPLEHONDPLQDWRPLDVWQLHMHVWSRáF]RQD]SRGáR*HP
W przegubach 1 i 2
QD F] ü
II
XNáDGX G]LDáDM QLH]QDQH RGG]LDá\ZDQLD
H
1
, V
1
, H
2
i V
2
.
2GG]LDá\ZDQLD SLRQRZH
V
1
i V
2
PR*HP\ Z\]QDF]\ü ]DSLVXMF UyZQDQLD UyZQRZDJL GOD
F] FL
II
: UyZQDQLX PRPHQWyZ Z]JO GHP SXQNWX
1
GOD F] FL
II
Z\VWSL W\ONR
niewiadoma V
2
QDWRPLDVWPRPHQW\VLá
H
1
, V
1
i H
2
Z]JO GHPSU]HJXEX
1
VUyZQH]HUXJG\*
LFKOLQLHG]LDáDQLDSU]HFKRG]SU]H]SXQNW
1.
∑
=
i
II
i1
M
0 : V
2
Â
l
í
II
p
W
Â
l
í
II
t
W
Â
3
2
l = 0
⇒
V
2
=
3
14
ql
: FHOX Z\]QDF]HQLD VLá\
V
1
PR*HP\ ]DSLVDü UyZQDQLH U]XWyZ VLá QD R SLRQRZ OXE
UyZQDQLHPRPHQWyZZ]JO GHPSXQNWX
2
GODF] FL
II
5yZQDQLHU]XWyZVLáQDRSLRQRZ
PDSRVWDü
0
=
∑
i
II
iy
P
: V
1
+ V
2
í
II
p
W
í
II
t
W = 0
⇒
V
1
=
3
16
ql
1
2
H
1
H
2
V
2
V
1
II
p
W
l
l
II
t
W
l
3
4
3
2
l
2 l
II
II
6 q
4 q
1
2
H
1
H
2
V
2
V
1
I
4 q
= 60
o
l
l
3 l
2 l
2 l
P = 3 ql
= 60
o
1
A
H
A
M
A
V
A
B
C
2
R
B
R
C
H
1
H
2
V
2
V
1
III
6
.RU]\VWDMF]Z\]QDF]RQHMZDUWRFL
V
1
QDVFKHPDFLHVLáDR]QDF]RQDMHVWF]DUQ\PNRORUHP
]DSLV]HP\UyZQDQLDUyZQRZDJLGODF] FL
I
XNáDGX
=UyZQDQLDU]XWyZVLáQDRSLRQRZGODF] FL
I
REOLF]\P\ZDUWRüUHDNFML
V
A
.
∑
=
i
I
iy
P
0 : V
A
í
V
1
= 0
⇒
V
A
=
3
16
ql
-DNRNROHMQH]DSLV]HP\UyZQDQLHPRPHQWyZZ]JO GHPSXQNWX$GODF] FL
I
XNáDGX
∑
=
i
I
iA
M
0 :
í
M
A
í
V
1
Â
l = 0
⇒
M
A
=
í
3
16
ql
2
Niewiadome reakcje R
B
i R
C
Z\]QDF]\P\NRU]\VWDMF]UyZQDUyZQRZDJLGODF] FL
III )
XNáDGX:DUWRüRGG]LDá\ZDQLD
V
2
MHVWMX*]QDQDDZL FQDVFKHPDFLHVLáDWDMHVWR]QDF]RQD
kolorem czarnym.
=DVWSLP\ REFL*HQLH FLJáH G]LDáDMFH QD F] ü
III
XNáDGX VLá Z\SDGNRZ
III
t
W
,
QDWRPLDVWVLá VNXSLRQ
P
MHMVNáDGRZ\PLSLRQRZLSR]LRP
1
A
H
A
M
A
V
A
H
1
V
1
=
3
16
ql
I
l
l
3 l
2 l
B
C
2
= 60
o
R
B
R
C
H
2
P
x
= 3 ql
ÂFRV
=
2
3
ql
P
y
= 3 ql
ÂVLQ
=
2
3
ql
V
2
=
3
14
ql
3
8
l
3
4
l
III
t
W
=
2
1
Â
q
Â
l = 8 ql
III
l
3 l
2 l
B
C
2
4 q
= 60
o
P = 3 ql
= 60
o
R
B
R
C
H
2
V
2
=
3
14
ql
III
7
= UyZQDQLD PRPHQWyZ Z]JO GHP SXQNWX
C
GOD F] FL
III
Z\]QDF]\P\ UHDNFM
R
B
.
0RPHQW\SR]RVWDá\FKQLHZLDGRP\FKVLá
H
2
i R
C
Z]JO GHPSXQNWX
C
VUyZQH]HUXJG\*LFK
OLQLHG]LDáDQLDSU]HFKRG]SU]H]WHQSXQNW
0
=
∑
i
III
iC
M
:
III
t
W
Â
3
8
l + V
2
Â
l
í
P
y
Â
l
í
R
B
Â
l = 0
⇒
R
B
=
3
37
ql
5HDNFM
R
C
Z\]QDF]\P\]UyZQDQLDU]XWyZVLáQDRSLRQRZGODF] FL
III
XNáDGX
0
=
∑
i
III
iy
P
: R
B
í
V
2
í
P
y
+ R
C
ÂVLQ
í
III
t
W
= 0
⇒
R
C
=
9
3
11
ql
1LHZLDGRP
H
A
PR*HP\Z\]QDF]\ü]UyZQDQLDU]XWyZVLáQDRSR]LRPGODFDáHJRXNáDGX
0
=
∑
i
ix
P
: H
A
í
R
C
ÂFRV
í
P
x
= 0
⇒
H
A
=
9
3
10
ql.
:\]QDF]HQLH UHDNFML GUXJLP VSRVREHP MHVW NRU]\VWQLHMV]H JG\* QLH ZL*H VL ]
NRQLHF]QRFL UR]ZL]\ZDQLD XNáDGX GZX UyZQD ] GZLHPD QLHZLDGRP\PL 1DOH*\ MHGQDN
GRGDWNRZR Z\]QDF]\ü RGG]LDá\ZDQLD SLRQRZH
V
1
i V
2
w przegubach 1 i 2
FKRFLD* Z
SROHFHQLX GR ]DGDQLD QLHZLDGRPH WH QLH E\á\ Z\PLHQLRQH 1DWRPLDVW QLH Z\]QDF]DP\
RGG]LDá\ZD SR]LRP\FK
H
1
i H
2
JG\* Z *DGQ\P UyZQDQLX UyZQRZDJL Z\NRU]\VW\ZDQ\P
GR UR]ZL]DQLD ]DGDQLD QLH SRMDZLDM VL WH QLHZLDGRPH =H Z]JO GX QD LGHQW\F]QH Z\QLNL
UR]ZL]DQLD ]DGDQLD SU]\ ]DVWRVRZDQLX REX VSRVREyZ SRPLMDP\ SRZWyUQH Z\NRQDQLH
sprawdzenia.