Solved University Question Papers May-2019

Solved University Question Papers

May-2019

Engineering Mechanics

Semester-II (Mechanical / Civil) Regulation 2017

[Time: Three Hours] [Maximum Marks: 100]

Answer ALL Questions

AU Solved Paper (80179)

PART A - (10 × 2 = 20 Marks)

Q.1

State the principle of transmissibility with an example. 

[Refer Two Marks Q.9 of chapter - 1]

Q.2

Give two practical applications, from where the concept of cross product evolved. 

[Refer Two Marks Q.27 of chapter - 1]

Q.3

Hinged support has two reactions - Justify.

[Refer Two Marks Q.12 of chapter - 4]

Q.4

Find the moment of a force = (200 i + 100 j) N acting a point 'A' (2i + 3j) m from the origin. 

[Refer Two Marks Q.19 of chapter - 3]

Q.5

Locate the centroid of the given shapes. 

[Refer Two Marks Q.12 of chapter - 5]

Q.6

Using parallel axis thereom find the area moment of inertia of a given area about x-axis. 

[Refer Two Marks Q.8 of chapter - 6]

Q.7

a) Carom board players employ −−−− principle while playing.

[Refer Two Marks Q.28 of chapter - 9]

b) Snow bowling game employs −−−− principle

Q.8

Write the Newton's law of motion for downward motion.

[Refer Two Marks Q.27 of chapter - 9]

Q.9

Define angle of repose. 

[Refer Two Marks Q.6 of chapter - 8]

Q.10

What do you mean by general plane motion ?

[Not in New Syllabus]

PART B - (5 × 13 = 65 Marks)

Q.11 

a) A disabled automobile is pulled by means of two ropes as shown. Knowing that the tension in rope AB is 3750 N. Determine by trigonometry the tension in rope AC and the value of a. so that the resultant force exerted at A is a 6000 N force directed along the axis of the automobile. 

[Refer example 2.10.50]

OR

b) A 200 kg cylinder is hung by means of two cables AB and AC, which are attached to the top of a wall. A horizontal force P perpendicular to the wall holds the cylinder in the position shown. Determine the magnitude of P and the tension in each cable.

[Refer example 2.12.24]

Q.12 

a) i) For the brake pedal shown in Fig. 5, determine the magnitude and direction of the smallest force P which has a 104 Nm clockwise moment about B. 

[Refer example 3.10.21]

ii) A 300 N force is applied at A as shown in Fig. 6. Determine: 1) The moment of force abut D, 2) The smallest force applied at B, which creates same moment. 

[Refer example 3.10.22]

OR

b) Find the reaction at A and B for the beam loaded as shown in Fig. 7. 

[Refer example 4.6.38]

Q.13 

a) Find the centroid of the shaded area shown in Fig. 9 about X and Y axes. 

[Refer example 5.3.26]

OR

b) Find second moment of area of the shaded section shown in Fig. 10 about its centroidal axes. 

[Refer example 6.6.1]

Q.14 

a) An object weighing 80 N is pulled up on the smooth plane by a 75 N force as shown in Fig. 11. Determine the velocity of the object after it has moved 4 m. 

[Refer example 9.2.24]

OR

b) The magnitude and directions of the velocities of two identical smooth balls before they strike each other are as shown in Fig. 12. Assuming e = 0.6 determine the magnitude and direction of velocity of each ball after impact.

[Refer similar example 9.3.35]

Q.15 

a) A body resting on a horizontal plane required a pull of 200 N inclined at 40° to the plane to initiate the motion. It was also found that a push of 250 N inclined at 40° to the plane, just moved the body as shown in Fig. 13. Determine weight of the body and Co-efficient of friction. 

[Refer example 8.6.28]

OR

b) A block of weight 1600 N is in contact with a place incline 30° to horizontal. A force 'P' parallel to the plane and acting up the plane μ = 0.2 Find: i) The value of 'P' to just cause the motion, ii) The value of 'P' to prevent motion iii) The magnitude and direction of frictional force.

[Refer similar example 8.6.9]

PART C - (1 × 15 = 15 Marks)

Q.16 

a) Derive the expression for mass moment of inertia of sphere of radius R, about y-axis. 

[Refer example 7.4.3]

OR

b) Fig. 15 shows configuration of an engine mechanism. The dimensions are the Crank OA = 200 mm; connecting rod AB = 600 mm, distance of centre of mass from crank end, AD = 200 mm, At the istant, the crank has an angular velocity of 50 rad/s clockwise and an angular acceleration of 800 rad/s2. Calculate the

i) Velocity of D and angular velocity of AB

ii) Acceleration of D and angular acceleration of AB

iii) Point on the connecting rod which has zero acceleration at this instant. 

[Not in New Syllabus]