**SB. Roll No. ................**

**APPLIED MECHANICS**

**3**

^{rd}Exam/Common/0851/May09**Duration : 3 Hrs.**

1.
Fill in the blanks

a.
_______ is the branch of
mechanics which deals with bodies in motion.

b.
Acceleration is a ___ quantity.

c.
The parallelogram law of forces
can be applied to find the resultant of _____
copular forces.

d.
Moment of a force = __________
x moment arm.

e.
Centroid is a term used for
bodies having _______ only

f.
The force of friction acts
________ to the contacting surfaces.

g.
Efficiency _________ as the
load decreases.

Note
: Attempt any six parts.

Chose the correct one

I.
Engineering mechanics deals
mainly with

a.
Semi solids

b.
Deformable solids

c.
Rigid bodies

d.
None of these

II.
Kinematics is the branch of

a.
Statics

b.
Dynamics

c.
Kinetics

d.
None of these

III.
For a force system, equilibrant
force is

a.
Parallel to resultant force

b.
Perpendicular to resultant
force

c.
In the line of action of
resultant force but in opposite direction

d.
Done of the above

IV.
The conditions of equilibrium
for coplanar non concurrent force are

a.
Æ©H= Æ©V=0

b.
Æ©H=0 Æ©M=0

c.
Æ©V=0 Æ©M=0

d.
Æ©H=0 Æ©M=0

V.
Centroid of semicircle lies at the distance of ___ form the
base where R is the radius

VI. Frictional force (F) has the following relation with the
normal reaction (R) between the two surface in contact

a.
F = ÂµR

b.
F = Âµ

^{2}R
c.
F = Âµ/R

d.
F=R/Âµ

VII.
The relation for maximum mechanical advantage is given by

a.
1/m

b.
M

c.
M

^{2}
d.
M

^{2}. D
Note : Attempt any five
questions

2.

a.
Define and explain the parallelogram law of force.

b.
State lami’s theorem.

c.
Define varignon’s theorem of moments.

d.
Where does the centre gravity of following bodies lie?

a.
Hemisphere -
right circular cone - sphere

e.
Explain the difference between co – efficient of friction
and angle of friction.

f.
Differentiate between reversible and irreversible machine
and give necessary condition for them.

Note : Attempt any there
questions

2. The forces of 2N , 3N 4N, 5N and 6N are acting at one of the
angular points of a regular hexagon
towards the other five angular
points taken in order. Find the magnitude and direction of the resultant force.

3. A uniform beam weighing 60N is 6 m long. If weights of 40N
and 50N are suspended from its ends, at what point must the beam be supported
so that it may remains horizontal.

4. Find the position of Centroid of an unequal angle section
100 x 75 x 8 mm with its longer leg vertical.

5. In a lifting machine a load of 60 N is moved through a
distance 5 cm by an effort p moving a distance of 80 cm. Find the value of p if
the efficiency of machine is 65 %

6. A bock resting on a rough inclined plane whose inclination
with the horizontal is 20*. The minimum
force parallel to plane required just to move the block up the plane is
10N . if the coefficient of friction between the block and the plane is 0.23
fine the weight of block.

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