ME 2151 ENGINEERING MECHANICS

B.E./B.TECH.DEGREE SECOND SERIES EXAMINATIONS, MARCH/APRIL – 2012

REGULATIONS 2008

SECOND SEMESTER

ME 2151 ENGINEERING MECHANICS

MECHANICAL ENGINEERING - B SECTION

Time: Two Hours                                 Date: 02.04.2012                               Maximum:50 marks

ANSWER ALL QUESTIONS

PART – A                                                                                         (10 x 1 =20 marks)

1.     Define equilibrium and equilibrant.

2.     Write the necessary and sufficient equations for equilibrium of spatial non concurrent and non parallel forces.

3.     Define statically determinate and indeterminate beams.

4.     What are the steps to be followed in drawing free body diagram?

5.     Define Pappus & Guldinus theorems.

6.     State parallel axis theorem and perpendicular axis theorem.

7.     State D’Alembert’s principle.

8.     State the difference between impulse and momentum

9.     State Laws of friction

10.                        Define Angle of Repose

PART – B                                                                                                                  (5 x 8 =40 marks)

11.                        Determine the tension in the cables AB, AC and AD as shown in fig.

12.                        Calculate the support reactions of the truss shown in fig.

13.                        Find the principal moment of inertia, Radius of Gyration and Polar Moment of Inertia of the section shown in fig.

14.                        Two blocks of mass 20 Kg and 40 Kg are connected by a rope passing over a frictionless pulley as shown in fig. Assuming the co-efficient of friction as 0.3 for all the contacting surfaces, find the tension in the string, acceleration of the system. Also compute the velocity of the System after 4 seconds starting from rest using

a.     D’Alembert’s principle

b.     Work Energy method

c.      Impulse Momentum Method

15.                        The ladder shown in Fig. is 6 m long and is supported by a horizontal floor and vertical wall. The coefficient of friction between the floor and the ladder is 0.35 and that between the wall and the ladder is 0.30. The weight of ladder is 150 N and may be considered as acting through mid-point. The ladder also supports a vertical load of 800 N at C which is at a distance of 1m from B. Determine the least value of α at which the ladder may be placed without slipping. Determine the reactions at that stage.