Define force. Discuss its characteristics.
[3 marks]Define :(i) Modulus of elasticity (ii) Stain (iii) Volumetric strain ( iv) Shear stress
[4 marks]Determine resultant of coplanar concurrent force system shown in fig.1.
[7 marks]Explain: Thermal stress
[3 marks]The equilateral triangle of 50 mm side as shown in fig. 2 is subjected to three forces. Third force is unknown force alongside AC. If the resultant of force system is pure couple, find third unknown force and its direction.
[4 marks]Calculate the total change in length for the steel bar shown in fig.3.
[7 marks]The rail in railway track is designed to have no stress at temp of 10˚C. If the temperature rises to 50˚C , find the maximum stress produced in rail. Take E = 200 Gpa , α = 11.7 x 10-6 /˚C
[7 marks]If no allowance is made for expansion. (ii) If allowance of 1.25 mm expansion is made for every 10 m length of rail
[ marks]State Lami’s theorem and explain its significance in mechanics.
[3 marks]Differentiate: (i) Resultant & Equilibrant (ii)Moment & Couple
[4 marks]Determine support reactions for the beam shown in fig. 4.
[7 marks]Define: (i) Bending moment diagram (ii) Point of Zero shear (iii) Point of contra flexure
[3 marks]Enlist and explain types of beam with necessary sketch.
[4 marks]Draw shear force and bending moment diagrams for the beam shown in fig.5.
[7 marks]Differentiate between static friction, dynamic friction and limiting friction.
[3 marks]State parallel and perpendicular axes theorems and its applications.
[4 marks]Aladder 5.2 m long, weighing 250 Nis placed against a smooth vertical wall with its lower end 2 m from the wall. The co-efficient of static friction between the ladder and the floor is 0.25. Aman weighing 70 kg starts climbing the ladder; determine the distance ‘x’ of man from the wall so that the ladder starts slipping.
[7 marks]Define: (i) Neutral Layer (ii) Section Modulus (iii) Radius of Curvature
[3 marks]The cross-section of the beam is a rectangle 60 mm x 80 mm deep. The maximum shear stress in the section is 45 MPa. Calculate shear stress at a section: (i) 40 mm above NA (ii) 20 mm above NA
[4 marks]Find centroid of area shown in fig. 61
[7 marks]Draw shear stress distribution diagram for I, Tand Lsections.
[3 marks]Derive relationship between rate of loading, shear force and bending moment.
[4 marks]Prove with usual notations the bending equation: M/I = f/y = E/R
[7 marks]What do you mean by Principal Planes and Principal Stresses?
[3 marks]Asteel shaft 50mm diameter and 0.5m long is subjected to a twisting couple of 103 N.m; the total angle of twist being 0.6°. Find the maximum shearing stress developed in the shaft and modulus of rigidity.
[4 marks]At a point in a strained body there are normal stresses of 100 MPa and 60 MPa both tensile together with a shear stress of 30 MPa, acting on two mutually perpendicular planes. Locate the principal planes and principal stresses. Also find the maximum shear stress. C 40 N A B 40 N Fig.2 Fig.1 Fig.3 Fig.4 Fig. Fig.5
[6 marks]