Deemed University 2010 B.Tech Mechanical Engineering University: Lingayas University Term: III Title of the : Engineering Mechanics - Question Paper
Roll No. ..
Lingayas University, Faridabad
Examination May, 2010
Course: B.Tech. Year: IInd
Semester: III Paper Code: ME-205E
Subject: Engineering Mechanics
[Time: 3 Hours] [Max. Marks: 100]
Before answering the question, candidate should ensure that they have been supplied the correct and complete question paper. No complaint in this regard, will be entertained after examination.
Note: Attempt any five questions. Assume suitable missing data, if any
Q. 1 (a) Determine the equivalent force couple system at the origin for the case of forces being applied to the edge of a circular disc as in Figure 1. Replace this force couple system with a stand alone force. (5)
(b)Replace the forces and couple in the Figure 2 by an equivalent force and couple at point A using vector mathematics. (15)
Q.2 (a) Draw tire free body diagram of (i) Complete system (ii) The cylinder and (iii) member AC in Figure 3. (5)
(b)Determine the forces in all the members of the truss as shown in the Figure 4 using joint method. 15
Q-3. (a) Define centroid, center of mass and center of gravity. Under what conditions the three will coincide. (5)
(b) Find Moment of Inertia about X and Y axis for the shaded area as shown in the Figure 5. (15)
Q-4. (a) Explain the D Alemberts principle. (5)
(b) A cannon fires its projectile with such an initial velocity and at such an angle of elevation that the range is R and the maximum height to which the projectiles rises is H. Find the maximum range that can be obtained with the same initial velocity. (15)
Q-5. (a) Explain work and energy principle for a system of particles. (5)
(b) The two blocks shown start from rest. The horizontal plane and the pulley are frictionless, and the pulley is assumed to be of negligible mass. Determine the acceleration of each block and the tension in each cord.
Q-6.(a) State and explain Hamiltons Principle. (5)
(b) Explain what is meant by stability of an equilibrium. (5)
(c) A ladder AB of length l and weight W stands in a vertical plane supported by smooth surfaces at A and B. Using the principle of virtual work, find the magnitude of horizontal force P to be applied at end A if ladder is to be in equilibrium. Refer Figure 8. (10)
Q-7. (a) Explain 'Coriolis acceleration with the help of an example. (5)
(b) Explain 'Principle Axes' with reference to Moment of Inertia of an Area. (5)
(c) Locate the centroid of the shaded area obtained by removing a semicircle of diameter 'a' from a quadrant of a circle of radius 'a' as shown in Figure 9.
(10)
Q-8. (a)A ball of mass 100gm is moving towards a bat with a velocity of 25 m/s as shown in figure 10. When hit by a bat the ball attains a velocity of 40m/s. If the bat and the ball are in contact for a period of 0.015 s. Determine the average impulse force exerted by the bat on the ball during the impact. (10)
(b) The acceleration of a particle is given by the relation a = 90-6x2 where 'a' is expressed in cm/s2 and 'x' in cm. If the particle starts with zero initial velocity at position x = 0, determine (i) the velocity when x = 5 cm (ii) the position where velocity' is again zero and (iii) the position where the velocity is maximum. (10)
| Earning: Approval pending. |
