Engineering Science

1a. A tie bar has two holes with a distance of 5m apart. By how much will the distance increase if a tensile load of 20kN is applied to the tie bar? the tie bar has a retangular section of 50mm*15mm and has Young's modulus of 200Gpa.
b. The Young's modulus of an aluminium alloy is 72*10^9 N/m^2. Calculate the maximum pull that can be applied to a 1.2m long circular rod made of this material if it must not be extended by more than 3mm. The diameter of rod is 8mm.
c. Steel rods of diameter 10mm and 15mm are connected to either end of a copper bar of doameter 20mm as shown below. The 10mm diameter steel rod has a length of 600mm;the 15mm diameter rod has a length of 400mm and the copper rod has length of 800mm. Determine the stresses in each of the rods and the total elongation if the composite is subjected to an axial tensile force of 15kn. The steel has a modulus of elasticity of 205Gpa and the copper one of 105 Gpa


15kN
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15kN