In a laboratory, a student is carrying out a tensile test for a sample of diameter 40mm with 700mm in length. The rod is subjected to an axial tensile load of 50000N and the Young's modulus of the sample is 20000N/mm2. It is assumed that the sample is still in the elastic state during the application of the stress. (a) Calculate the stress applied to the rod. (b) (c) (3 marks) Calculate the length of the rod when the stress is applied. (8 marks) Draw a typical stress-strain curve with labels for the metal rod when it is subjected to a tensile force and explain the terms "elasticity" and "plasticity". (10 marks) (d) Briefly describe the following terms:- (i) Fatigue (ii) Factor of safety (2 marks) (2 marks)