Question 1 (15 marks) A large steel plate is being lowered into position by a crane and is attached to the crane via a cable sling, see Figure Q1. It can be considered to be in equilibrium. The steel plate is 1.5 m wide, 0.75 m tall, 0.2 m thick (not shown in the figure) with a density of 8100 kg/m. The attachment points of the sling are 1.4 m apart and form an angle of 45 to the vertical. All cables have a diameter of 12 mm and are made from steel which has a Young's modulus of 210 GPa. (1a) Determine the tensile forces in the angled and vertical cables. (1b) Determine the stresses in the angled and vertical cables. (4 marks) (1c) If the steel in the cables has a yield stress of 150 MPa, how much thicker could the steel plate be made before it causes yield in the steel cables ? (3 marks) 45 45 1.4 m 1.5 m Figure Q1 (8 marks) 0.75 m NB: This question was obtained from ECM2114 Solid Mechanics (January 2019) exam paper. Numeric solutions: 1a) 12629.3 N, 17860.5 N; 1b) 111.67 MPa, 157.9 MPa; 1c) 0.19 m