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Papers of engineering mechanics |

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Re: Papers of engineering mechanics
As you want I am here giving you question paper of Engineering Mechanics of BTECH Mechanical engineering course of Anna University Sample questions :1. Define the following terms : (a) Coplanar forces (b) Concurrent forces. 2. What i s the difference between a resultant force and equilibration force? 3. What is meant by free body diagram of a rigid body? 4. Write the conditions of equilibrium of a system of parallel forces acting in a plane. 5. De¯ne radius of gyration with respect to x-axis of an area. 6. State parallel axis theorem with simple sketch. 7. The angular rotation of an accelerated disc is given by µ = (9=32)t3 + (3=4)t2 + 6t radians. Find its angular acceleration when t = 2 sec. 8. What i s linear momentum? 9. Define : Coefficient of static friction. 10. A body is rotating with an angular velocity of 5 radians/sec. After 4 seconds, the angular velocity of the body becomes 13 radians/sec. Determine the angular acceleration of the body. Part B - (5 x 16 = 80 Marks)11. (a) (i) Determine the resultant of the concurrent force system shown in the fol- lowing (Marks 8) (ii) The following figure shows a 10 kg lamp supported by two cables AB and AC. Find the tension in each cable. (Marks 8) OR 11. (b) Forces 32 kN, 24 kN, 24 kN and 120 kN are concurrent at origin and are respectively directed through the points whose coordinates are A(2, 1, 6), B (4, -2, 5), C (-3, -2, 1) and D (5, 1, -2). Determine the magnitude of the resultant and the angles it makes with coordinate axes. (16) 12. (a) (i) A force (10i + 20j ¡ 5k)N acts at a point P (4, 3, 2) m. Determine the moment of this force about the point Q(2, 3, 4) m in vector form. Also find the magnitude of the moment and its angles with respect to x; y; z axes. (Marks 8) (ii) A plate ABCD in the shape of a parallelogram is acted upon by two couples, as shown in the figure. Determine the angle ¯ if the resultant couple is 1.8 N.m clockwise. (Marks 8) OR 12. (b) Two beams AB and CD are shown in figure. A and D are hinged supports. B and C are roller supports. (i) Sketch the free body diagram of the beam AB and determine the reactions at the supports A and B. (Marks 9) (ii) Sketch the free body diagram of the beam CD and determine the reactions at the supports C and D. (Marks 7) 13. (a) (i) Derive, from first principle, the second moments of area Ixx and Iyy for the rectangular area when the axes are as shown below: (Marks 6) (ii) Derive, by direct integration, an expression for the second moment of area of a triangle, shown in figure, about x-axis. (Marks 10) 13. (b) (i) Calculate the centroid polar moment of inertia of a rectangular section with breadth of 100 mm and height of 200 mm. (Marks 4) (ii) Find the moment of inertia of the shaded area shown in figure about the vertical and horizontal centroid axes. The width of the hole i s 200 mm. (Marks 12) 14. (a) (i) A stone i s thrown vertically upwards from a point on a bridge located 40 m above the water. If it strikes the water 4 s after release, determine the speed at which the stone was thrown and the speed at which the stone strikes the water. (Marks 8) (ii) A bomb is dropped from an aerospace flying at a speed of 800 km/h at a height of 1500 m above the level ground. Find the horizontal distance covered by the bomb after its release. Also and the time required for the bomb to hit the target and the velocity with which the bomb hits the target. (Marks 8) OR 14. (b) A ball of mass 1 kg moving with a velocity of 6 m/s strikes another ball of mass 2 kg moving with a velocity of 2 m/s at the instant of impact the velocities of the two balls are parallel and inclined at 30± to the line joining their centers as shown in the figure. If the coefficient of restitution i s 0.5, find the velocity and the direction of the two balls after impact. Also calculate the loss in kinetic energy due to impact and the percentage of loss. (Marks 16) 15. (a) (i) Two blocks A and B of mass 50 kg and 100 kg respectively are connected by a string C which passes through a frictionless pulley connected with the fixed wall by another string D as shown in figure. Find the force P required to pull the block B. Also find the tension in the string D. Take coefficient of friction at all contact surfaces as 0.3. (8) (ii) In a belt drive, the smaller pulley is subjected to a tension T1 on the tight side and a tension T2 on the slack side. Derive a relation between these tensions in terms of the coefficient of friction and the angle of wrap. (Marks 8) OR 15. (b) The figure given below shows a stepped pulley. The smaller radius is 150mm and the bigger radius i s 200 mm. Two loads P and Q are connected by inextensible taut cords. Load P moves with an initial velocity of 0.2 m/s and has a constant acceleration of 0.25 m/s2 both downwards. Determine (i) The number of revolutions turned by the pulley in 4 seconds (Marks 6) (ii) Velocity and the distance traveled by load Q after 4 seconds. (Marks 5) (iii) Acceleration of point B located on the rim of the pulley at t = 0. Give both magnitude and direction. (Marks 5) Address:Anna University Sardar Patel Road Guindy Chennai, Tamil Nadu 600025 Map:
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