View
230
Download
0
Category
Preview:
Citation preview
8/8/2019 Statics- Final JULY08
1/11
e\\ e)/ . \ ; ' t
; \'f':*1.-**='rL---*, v .r '
Pa!.ar Masjldunii . , ir=!t! r-k.jd,or
9e1RgNA=
b
q/
,ilLIf] lfI
IAIII',TstNttt\lt7
UNIVERSITITEKNOLOGIPETRONAS
COURSE
DATE
TIME
VBB1O23 VAB1O23 ENGINEERING EGHANICS
STATICS OF RIGID BODIES
18 NOVEMBER 008 TUESDAY)
9.00 AM - 12.00 NOON 3 hours)
INSTRUCTIONS O CANDIDATES
1.
2.
3.
Answer FIVE 5) ou t of SIX (6)questions rom he Question ooklet.
Begin EACH answer n a new page n the Answer Booklet.
Where applicable, how clearly teps aken n arriving t the solutions nd
ind cate ALL assumptions.
Indicate learly nswers hat are cancelled, fany.
Do not open hi s Question ooklet ntil nstructed.
4.
5.
Note : There are ELEVEN 11)pages n this Question ooklet ncluding he
cover page.
Universit i Teknoloqi PETRONAS
8/8/2019 Statics- Final JULY08
2/11
VBB1O23VAB1O23
FIGUREQla shows a lampwitha mass of 15 kg and supported y a pole
AO and cables AB and AC. lf the force n the pole acts along ts axis,
Ceterming he orces n1\tQ, B, and AC or equilibrium.
I no -- _ o - 661 parq - c? 196 frr
6' ?oF
, .43 rrg + 0.4>1 f:pt
- t ; . j t t l3 - o.>t9J:
' , : . ae " f *) t : t id ' t t
-\.
"5 ,?L : _ d\". / _!"9 t t tz
jr t . --- | 4I) {Fa
I l tr.
t
[8 marks]
b. FIGURE Ql b shows pole AB which supports a traffic ight of weight
200 N. Determine he moment ector f the weight f the raffic ight aboutthe base of the pole along x-axis. ake = 30"
2
Bi
FIGUREQlb
2
FIGUREQla
[4 marks]
8/8/2019 Statics- Final JULY08
3/11
r,
VBB1O23 VAB1O23
FIGURE Q1c shows cables which exert orces on pore AB. The pole ssupported by a ball-and-socket oint at its base and the forcesF1 = (70i - 121.2j) N and Fz = (-75j) N . Determine he components
freaction t A.
[8 marks]
FIGUREQ1c(t
3
-
8/8/2019 Statics- Final JULY08
4/11
VBB1O23 VAB1O23
FIGUREQ2a shows a loaded oof russ. Take = 30 :1
Determine he support eactions t A AND D.
[2 marks]
Calculate he orces n members B,AF,BC, F, FC & FE ofthe truss using the method of joints AND state if the
members re n tension r compression.
[8 marks]
il .
1m
3fi lrl\l f*XkHFIGURE Q2a
4
8/8/2019 Statics- Final JULY08
5/11
VBB1O23 VAB1O23
FIGURE Q2b shows a loaded russ.
1S kN
@
E
s
I ' l . l ' l . i '* J* *t --L J"*mr4mr4mr4mr4mF4FIGUREQ2bDetermine he reaction t the supports AND l.
[2 marks]
Catculate he forcesn the members EF and EL using he methodof sections AND state if the members are in tension or
compression.
[8 marksJ
[ .
a)
4il kt{
5
8/8/2019 Statics- Final JULY08
6/11
\
VBB1A23 VAB1O23
FIGUREQ3a shows a beam AB with negligible ass and hickness..lt ssubjected o a uniformly istributed oading f 800 Nlm. lt is supported tone end by a pin and at the other end by a post of mass 50 kg andnegligible hickness. Determine
he minimum orcep
needed o move hepost. The coefficients f static riction t B and C are pe = 0.4 and p6 = 0.2respectively.
FIGUREQ3a
[10 marks]
fiil0 NJm
6
8/8/2019 Statics- Final JULY08
7/11
b.
VBB1O23I ABlO23
FIGURE Q3b shows a wedge used o level he member AC. Determine
the reversed orizontal orce P that must be applied o pull he wedge out
to the left.The coefficient f static rictionbetween he wedge and he wo
surfaces of contact t p"=
0.15 . Neglect he weight of the wedge. Take0=5".
!fiOmm
fi kFl
mm
FIGURE Q3b
[10marks]
FG
w
d\ '
V
\
(^a rJ
\J
\1q50
{E KI{
8/8/2019 Statics- Final JULY08
8/11
FIGUREQ4 gives he cross section f a beam.
VBBIO23 VAB1O23
Take = 50 mm.. l
Q}
FIGUREQ4
Determine he:
i. centroid or the shaded portion.
v
[8 marks]
moment f inertia or the shaded portionabout he x axis.
[4 marks]
product f inertia or the shaded portion bout he x and y axes.
[8marks]
8
8/8/2019 Statics- Final JULY08
9/11
vBB1023 VAB1023
FIGUREQSa shows a crate of mass 200 kg suspended rom he cablB fa crane. Determine he force n the cable at time, = 2 s if the crate smovingupward with:
i . a constantvelocity=2mls.
[4 marks]
ii . a speed f v = (0.2( +2) mls where is n seconds.
[4 marks]
.v
J
9
FIGURE Q5a
8/8/2019 Statics- Final JULY08
10/11
\t
VBB1O23VAB1O23
b' FIGURE Qsb shows block B which rests on a smooth surface. f thecoefficients s static and kinetic rictionbetween A and B are Fs = 0.4 andlJx= Q'3, espectively, etermine he acceleration f each btosrl
8/8/2019 Statics- Final JULY08
11/11
a..
VBBI023 VABI023
FIGURE Q6a shows a motor ha t gives disk A a clockwise ngularacceleration a = (0.6F + 0.75) ad/s2, here is in seconds. f the nitialangular elocity f the disk s &ro 6 rad/s, determine he magnitudes f
the vefocity nd acceleration f blockB when = 2 s.[10marks]
FIGURE Ga
FIGUREQ6b shows a 2-kg ball hrown t the suspended 0-kgblockwitha velocity f 4 m/s. f the coefficient f restitution, , between he ballandthe block s 0.8, determine he maximum eight to which he blockwillswing before t momentarily tops.
[10 marks]
FIGUREQ6b
-END OF PAPER.
k"
b.
5"
11
Recommended