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**KERALA TECHNOLOGICAL UNIVERSITY**

## SECOND SEMESTER B.TECH. DEGREE EXAMINATION, MAY/JUNE 2016

## KTU STUDENTS

**Course Code:BE100 Course Name:ENGINEERING MECHANICS**

**Max. Marks:100 Duration : 3 Hours**

**PART— A**

**Answer all the questions. Each question carries 5 Marks. (8x5=40 Marks)**

1. Explain the principle of transmissibility with an example.

2. Three smooth identical spheres A, B and C are placed in a rectangular channel as shown in Fig1. Draw the free body diagram of each sphere.

3. State and prove Parallelaxis theorem.

4. Define angle of friction and angle of repose. Prove that angle of repose is equal to angle of friction

5. A Iift carries a weight of 3600 N and is moving with a unitorm acceleration of 3.5 m/S^2. Determine the tension in the supporting cable when the lift is moving upward. (g = 9.8m/s^2).

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

7- Distinguish between Simple Harmonic Motion and Periodic motion.

8. Expiainthetypes ofvibrations.

**PART— B**

**Answer two questions from each set :**

**SET 1 : Answer any 2 questions. Each question carries10 Marks. (2x10=20 Marks)**

9.Determine the magnitude and direction of the resultant of the forces acting on the ring as shown in Fig. 2.

10. Two smooth circular cylinders each of weight 100 N and radius 15 cm are Connected at their centres by a string AB of length 40 cm and rest upon a horizontal plane as shown in below Fig. 3. The cylinder above them has aweight 200 N and radius of 15 cm.Find the force in the string AB and the pressure produced in the floor at the points of contact D and E.

11. A 5m bar of nefgligible weight rests in a horizontal position on the smooth ptanes as shown in above Fig. 4.Determine the load P andreaotions at supports.

**SET 2 : Answer any 2 questions. Each question carries 10 Marks. (2x1 0 = 20 Marks)**

12.a) Define radius of gyration.

b )Find the Centre of Gravity for the un-shaded composite area shown in Fig.5.

13.Determine the moments of inertia of the shaded area (Fig. 6) with respect to the x and y axes.

14. A uniform ladder of 4 m length rests againsta vertical wallwith which it makes an angle of 45°. The coefficient of friction between ladder and the wall is 0.4 and that between ladder and the floor is 0.5. If a man whose weight is one haltthat oi ladder climbs up then how high will it be when the ladder slips?

**SET 3 : Answer any 2 questions .Each question carries 10 Marks.(2x10=20 Marks).**

15. A lift has an upward acceleration of 1.2m/s2. What force will a man weighing 750 N exert on the floor of the lift ? What force would he exert it the lift had an acceleration of 1.2 m/s2 downwards ? What upward acceleration would cause his weight to exert a force of 900 N on the floor ?

16.

in the reciprocating engine mechanism shown in Fig.7, the crank OA rotatesat

uniform Speed of 300 rpm. The length of the crank and connecting rod are 12 cm and 50 cm respectively. Find the angular velocityot the connecting rodand velocity of the piston when the crank makes an angle of 30° with horizontal.

17.A body moving with SHM, has an amplitude of 1 m and period of oscillation is 2 seconds. Find the velocity and acceleration of the body at t=0.4 second , when the time is measured from mean position and extreme position ?

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