Statics- Final JULY08

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


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]


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

-


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


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


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


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{


8/11

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


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


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


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

Documents

Statics- Final JULY08