Section A
Q1.
(a)
A 10 m boom AB weighs 1 kN. The distance of centre of gravity is 5 m from A. For the position shown in the figure given below, determine the tension T in the cable and reaction at A:
6 3 kN 30° ikN
(a)
A rope making 1¼ turns around a stationary horizontal drum is used to support a weight as shown in the figure given below. If the coefficient of friction is 0.3, what range of weight can be supported by exerting an 800 N force at the end of the rope?
6 800 N W
(b) A steel tube of 100 mm internal diameter and 10 mm wall thickness in a plant is lined internally with well-fitted copper sleeve of 2 mm wall thickness. If the composite tube is initially unstressed, calculate the hoop stress set up assumed to be uniform throughout the wall thickness, in a unit length of each part of the tube due to an increase in temperature of 100 °C. For steel, E = 208 GPa, α = 11 × 10-6 /°C For copper, E = 104 GPa, α = 18 × 10-6 /°C 12
(c) What is kinematic pair? How are kinematic pairs classified? Explain. 6
(c) A four-bar mechanism has the following dimensions: DA = 200 mm, CB = AB = 300 mm, DC = 500 mm The link DC is fixed and the angle ADC is 60°. The driving link DA rotates uniformly at a speed of 100 r.p.m. clockwise and constant driving torque has the magnitude of 50 N-m. Determine the velocity of point B and angular velocity of the driven link CB. If the efficiency is 70%, calculate also the resisting torque : 6
