Download SGBAU B-Tech 2nd Sem FPOPC Poly Plast Engineering Mechanics Question Paper

Download SGBAU (Sant Gadge Baba Amravati university) B-Tech/BE (Bachelor of Technology) 2nd Sem FPOPC Poly Plast Engineering Mechanics Previous Question Paper

B.chh. Second Semester ((FPOPC) Polymer (Plastic)) (CGS)
11710 : Engineering Mechanics : 2 SCT.3
P. Pages : 4 l?l?ll'? AW - 2932
Time : Three Hours . o 9 l. 7 .. Max. Marks : 80
Notes : 1. Answer three question from Section A and three question fror? Section B.
2. Assume suitable data wherever necessary.
3. Illustrate your answer necessary with the help of neat sketches.
4. Use of pen Blue/Black ink/re?ll only for writing the answer book.
SECTION - A
1. a) State and explain different system of forces. ~i
b) State and explain law of polygon of forces. 3
c) Find the resultant of a given force system as shown in ?g. 1. 7
100N
700N -
Fig.1 ZOON _ - _
0R
2. a) De?ne couple and state its characteristics. 4
b) State and explain Varignon's theorem. 3
c) Determine and locate position of resultant ?R' for the forces acting on L-bent as shown in 7
?g. 2. Take reference point as 'A'.
E 20ka
501:}: I
30kN-
0.2m 1 C m
A B 45?
D
*_ + ??54
?I 0.4m 0.4m 0.4m Fig- 2
3. a) State analytical and graphical conditions of equilibrium. 3
b) State and explain Lami's theorem. . 3
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c) Determine the forces in the cables AB and AC loaded as shown in ?g. 3. 7
lOOON
Fig. 3
IZOON
0R
4. a) State and explain parallel axis theorem. 3
b) Determine moment of Inertia about centroidal axes for a plane lamina as shown in ?g. 4. 10
100mm
10mm
100mm
W______ T ?- _ - _
15mm Fig. 4
5. a) State assumption made in analysis oflmss. 3
h) De?ne perfect and imperfect trusses 3
c) Ana y se the truss loaded as shown m ?g.5 Tabulate the result. ' 7
\F??i3kN
m a; : B\C:m
Rollcr?l\l l
F?????+3kN Fig. 5
3m 3m
0R
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h)

a) State laws of dry friction. ' 4
b) De?ne : i 3
i) Angle of repose ii) Cone of friction
c) A uniform rod AB of length 2.5 m weighing 500 N is hinged at B with end ?A' resting on a 6
750 N block which in turn rests on a horizontal plane as shown in ?g. 6 Take [.1 = 0.3 for
all contact surfaces. Determine minimum value of 'P' required to start rightward motion of
the block.
3 .
Hinge
3
4
A 4 AB 2 2.5m
P
?' 7 0
5 N Fig. 6
//7/ ///7 ///l
SECTION - B
a) The rectilinear motion of a particle is de?ned by a = 6W where a is m/s2 and v is in m/s.
When I = 2 sec, v = 36 m/s and s = 30m. Determine displacement of particle when t = 3 sec.
b) A projectile is ?red from the edge of a 150 m cliff with an initial velocity of 180 m/s at 7
angle of 30? mm the horizontal.
Find: i__ - _... _ _ e-_
i) The greatest elevation above the ground reached by projectile.
ii) The horizontal distance covered before striking the ground.
OR
a) Two trains, one movin g at 90 mm: and other at 120 km/hr, are heading towards one another 7
on a straight level track. When they are 3 km apart, both drivers simultaneously see the
other's trains and apply their brakes. If the brakes decelerate each train at the rate of 1 m/s2
determine whether trains will collide or not ?.?
b) An automobile starting from rest speed upto 40 m/sec vn'th a constant acceleration of 4 m/s2 7
runs at this Rpecd for a time and ?nally comes to rem with deceleration of 5 mv?sZ. If L?ne total
distance travelled is 1200 m ?nd the IOLal time required.
a) State and explain D?Alembert's Principle. 3
b) Two blocks A and B are released from rest on a 30? incline when they are 18 m apart. The 10
coef?cient of friction under block A is 0.2 and the under the block B 18 O 4. In what time
block 'A' reaches the block B " Refer ?g 7.
B
P~
WA=100N
WB = 80N
Fig. 7
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10. 21)
h)
11. a)
b)
12. 3)
OR
Derive work-energy equation. 4
A body weighing 300 N is pushed up an inclined plane 30" with the horizontal. A 400 N 9
force is acting parallel to the plane. lf?an initial velocity of the body is l .5 m/s and coefficient
of friction is 0.2. Determine what velocity the body will have after moving 6m. Refer
?g. 8.
mw
3 0 ?
What is Reversible and irreversible machine ? 4
What load can be lifted by an effon of 120 N. if the velocity ratio is 18 and ef?ciency of 9
the machine at this load is 60% ?7
Determine law of machine. if it is observed that an effort of 200 N is required to li? a load
of 2600 N and ?nd the effon required to run the machine at a load of 3.5 kN.
OR
De?ne : 6
i) Mechanical Advantage
ii) Velocity Ratio
??-??-?i?7 -Ef?ciency ofamat?hmci' " **"? i' A";
b)
iv) Ideal machine
\I
In a differential wheel and axle, the diameter 01' the effort wheel is 400 mm. The radii of the
axle are 150 mm and 100 mm respcgtiveiy. The diameter of the rope is 10 mm. Find the
load which can be li?ed by an effort of 25 N assuming the ef?ciency of the machine to be
84%
r**********
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