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PEPERIKSAAN AKHIR SEMESTER IFINAL EXAMINATION SEMESTER I
SESI 2012/2013SESSION2012/2013
KOD KURSUS : SKKK1013COURSE CODE SKKK1013
KURSUS : STATIKCOURSE STATICS
PROGRAM : SKKPROGRAMME SKK
MASA : 0900 PAGI 1200 TENGAH HARI (3 JAM)TIME 0900A.M 1200 P.M (3 HOURS)
TARIKH : 14 JANUARI 2013 (ISNIN)DATE 14THJANUARY 2013 (MONDAY)
ARAHAN KEPADA CALON (INSTRUCTIONS TO STUDENT) :
1. Jawab SEMUA soalan.Answer ALL questions.
2. Mulakan jawapan untuk setiap soalan pada mukasurat yang baru.
Begin the answer to each question on a new page.
CLOSED BOOK
DILARANG MENIRU SEMASA PEPERIKSAANCOPYING IS PROHIBITED DURING EXAMINATION
________________________________________________________________________________KERTAS SOALAN INI TERDIRI DARIPADA 13 MUKA SURATBERCETAK
TERMASUK MUKA SURAT INI
THIS EXAMINATION PAPER CONSISTS OF 13 PRINTED PAGES INCLUSIVE OF THIS PAGE
FakultiKejuruteraan Kimia
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Question 1 (10 marks)
C01
a b
8 2
The two spring system BAC is shown at left (Figure 1a) below in its original, unstretched
position. After a force, F, is applied at some angle, , the stretched position is shown at right
(Figure 1b). Determine
a) The angle, (8 marks)
b) The magnitude of the force, F. (2 marks)
Figure 1
Question 2 (10 marks)
CO2 C03
a b
8 2
a) Determine the force exerted by the cable at B and the reactions at support A necessary for
equilibrium of the member ABC (Figure 2). (8 marks)
b) Draw a final picture of member ABC with forces correctly labeled and oriented.
(2 marks)
2 m
2 m
2 mkAB = 10 N/m
kAB = 20 N/m
A
B
C
B
A
C
F
(a) (b)
2 m
2 m
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Figure 2
Question 3 (20 marks)
C05
a b
14 6
a) The truss shown in Figure 3 is made from seven members, each having a mass per unit
length of 6 kg/m. Determine the position
(x, y) of the center of mass. Neglect the mass
of the gusset plates at the joints. Hint: treat as centroid of a line. (14 marks)
b) If the truss is supported by a pin at A and a roller at C, calculate the support reactions.
(6 marks)
Figure 3
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Question 4 (20 marks)
C05
a b
10 10
a) The storage tank shown in Figure 4 is fabricated from thin steel plate. If one liter of
paint can cover 3m2 of the tanks surface, determine how many liters of paint are
needed to cover the total outside surface area of the tank. (10 marks)
b) Determine the total volume of the storage tank shown in Figure 4. (10 marks)
Note: Please solve these questions (4(a) and 4(b)) using the theorem of Pappus-
Guldinus.
Figure 4
Question 5 (20 marks)
C0420
Consider the truss system in Figure 5 below. All members are subjected to a force not
exceeding 2.0 kN tensile force or 1.5 kN compressive force. Analyze the system to determine
the maximum force P that can be applied to the truss system. Show that all members satisfy
the condition. Identify if there is a possible of zero-force member. (20 marks)
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Figure 5
Question 6 (20 marks)
CO6
a b
10 10
a. A roll of paper has a uniform weight of 3 N and is suspended from the wire hanger so
that it rests against the wall (Figure 6a). If the hanger has a negligible weight and the
bearing at O can be considered frictionless, determine the minimum force P needed to
start turning the roll if angle = 30. The coefficient of static friction between the wall
and the paper is s = 0.25. (10 marks)
Figure 6a
b. The two stone blocks (Figure 6b) have weights of WA = 2.5 kN and WB = 0.75 kN.
Evaluate the system and determine the smallest horizontal force P that must be applied
to block A in order to move this block. The coefficient of static friction between the
blocks is s = 0.3, between the floor and each blocksf = 0.5 and between the block B
P P
DCBA
F E
3 m
3 m 3 m 3 m
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and wall is sw = 0.2. (Hint: Draw the free-body diagram before solving the question).
(10 marks)
Figure 6b
45
AB P
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Soalan 1 (10 markah)
C01
a b
8 2
Dalam Rajah 1a, dua sistem spring BA dan AC menunjukkan kedudukan asal spring iaitu
sebelum diregangkan. Selepas daya, F dikenakan pada sudut, , kedudukan asal spring berubah
dan menjadi regang seperti yang ditunjukkan pada Rajah 1b.Tentukan
a) Sudut, apabila daya, F di kenakan pada spring di kedudukan A. (8 markah)
b) Magnitud daya, F. (2 markah)
Rajah 1
Soalan 2 (10 markah)
CO2 C03
a b
8 2
a) Tentukan daya yang dikenakan oleh kabel di B dan daya tindak balas pada sokongan A
yang diperlukan oleh anggota ABC untuk berada dalam kedudukan keseimbangan
(Rajah 2). (8 markah)
b) Seterusnya, lukiskan gambar akhir anggota ABC dengan kesemua daya dan arah yang
mana ia perlu dilabelkan dengan betul. (2 markah)
2 m
2 m
2 mkAB = 10 N/m
kAB = 20 N/m
A
B
C
B
A
C
F
(a) (b)
2 m
2 m
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Rajah 2
Soalan 3 (20 markah)
C05
a b
14 6
a) Kerangka dalam Rajah 3 terdiri daripada tujuh anggota yang setiap satunya
mempunyai jisim per unit panjang 6 kg/m. Tentukan kedudukan pusat jisim kerangka
(x, y). Abaikan jisim plet penyambung. Petunjuk: anggap seperti sentroid garisan.
(14 markah)
b) Jika kerangka mempunyai sokongan pin pada A dan sokongan bebola pada C, tentukan
daya-daya tindakbalas tersebut. (2 markah)
Rajah 3
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Soalan 4 (20 markah)
C05
a b
10 10
a) Tangki penyimpanan yang ditunjukkan dalam Rajah 4 diperbuat daripada kepingan
keluli nipis. Jika satu liter cat dapat meliputi permukaan seluas 3m2, tentukan berapa
liter cat yang diperlukan untuk mengecat keseluruhan permukaan luar tangki tersebut.
(10 markah)
b) Tentukan isipadu keseluruhan tangki penyimpanan dalam Rajah 4. (10 markah)
Perhatian: Sila selesaikan soalan 4(a) dan 4(b) dengan menggunakan teori Pappus-
Guldinus.
Rajah 4
Soalan 5 (20 markah)
C04
20
Perhatikan system kerangka dalam Rajah 5 di bawah. Semua anggota tertakluk kepada satu
daya tidak melebihi 2.0 kN daya regangan atau 1.5 kN daya mampatan. Analisa system ini
bagi menentukan daya maksimum P yang boleh digunakan bagi system kerangka itu.
Tunjukkan bahawa semua anggota memenuhi syarat yang dinyatakan. Kenalpasti jika terdapat
anggota daya-sifar. (20 markah)
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Rajah 5
Soalan 6 (20 markah)
CO6
a b
10 10
a. Satu gulung kertas mempunyai berat seragam 3 N dan tergantung daripada penyangkut
dawai supaya pegun bersandar pada dinding (Rajah 6a). Jika berat penyangkut
diabaikan dan penggalas pada O dianggap tanpa geseran, tentukan daya minimum P
yang diperlukan untuk memutarkan gulungan kertas jika sudut = 30. Pekali geseran
static antara dinding dan kertas adalah s = 0.25. (10 markah)
Rajah 6a
b. Dua biji batu blok (Rajah 6b) mempunyai berat WA = 2.5 kN dan WB = 0.75 kN.
Nilaikan sistem ini dan tentukan daya mendatar terkecil P yang mesti dikenakan ke atas
P P
DCBA
F E
3 m
3 m 3 m 3 m
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blok A untuk menggerakkan blok ini. Pekali geseran static antara sesama blok adalah
s = 0.3, antara lantai dan setiap blok adalah sf= 0.5 dan antara blok B dengan dinding
adalah sw = 0.2. (Hint: Lukis gambarajah jasad-bebas sebelum penyelesaian soalan).
(10 markah)
Rajah 6b
45
AB P
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Reactions at supports and connections
Support or connections Reaction Unknown
Force with known
line of action
Roller Rocker Frictionless surface
1
1
Short cable Short linkForce with known
line of action
1
900
Force with known
line of actionCollar on frictionless rod Frictionless pin in slot
2
Frictionless pin or hinge Rough surface Force of unknown
direction
or
3
Fixed support Force and couple
or