B

B2B109

Reg. No. Name:
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
SECOND SEMESTER B.TECH DEGREE EXAMINATION, MAY 2017

Course Code: BE 100
Course Name: ENGINEERING MECHANICS
Max. Marks: 100 Duration: 3 Hours
PART A
Answer all questions. 5 marks each.

1. State and explain the principle of Transmissibility of force with sketches.

2. The x,y,z components of a force are 36KN, -24kN and 241 respectively. Find the
components of this force along the line joining A(1,2,-3) and B(-1,-2,2).

3. Using first theorem of Pappus and Guldinus, find the surface area of a i) Sphere and
11) right circular cone.

4. Distinguish between (i) Static and kinetic frictions,(ii) Sliding friction and rolling
friction and (iii) angle of friction and angle of repose.

5. What do you mean by instantaneous centre of rotation? How can it be located fora
body moving with combined motion of rotation and translation?

6. What is a seconds’s pendulum? Derive expressions for the loss or gain of time due to
changes in length of string and gravitational acceleration in the case of a simple
pendulum.

7. Define the terms amplitude, period of oscillation and frequency in a simple harmonic
motion.

8. State D’Alemberts principle giving equations expressing the above Principle on the
motion of a lift moving upwards with an acceleration ‘a’ m/sec’ carrying a weight of
“WN.

PART B
Answer any 2 questions from each SET.
SET 1
Each question carries 10 marks.

9. ABCD is a rectangle in which AB=30mm, BC= 20mm. ‘E’ is the middle point of
‘AB’. Forces of magnitude 16,14,18,8,10 and 20N act along ‘AB’, ‘BC’, ‘CD’, ‘DA’,
‘EC’ and ‘DE’ respectively. Find the magnitude, direction and position with respect to
‘ABCD’ of single force to keep the body in equilibrium. ‘B’ is 10 right of ‘A’ and
taken in anticlockwise direction.

10. a. A cylindrical road roller of weight 1000N and radius 30 cm is pulled by a force ‘F’
through the centre of the wheel. While moving it comes across an obstacle of height
15 cm. Calculate the least force ‘F’ required to cross the obstacle . (5)

b. A force acts at the origin of a co-ordinate system in a direction defined by the
angles 0,=69.3° and a,=57.9° .Knowing that the "४९ component of the force is -174N,
determine the (i) angle ay and (ii) the other components and the magnitude of the
force. (5)

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