Q1) (55 pts.) The S-N (fatigue life) diagram for a material is given below: a) What is the endurance limit of the material? b) What is the fatigue strength corresponding to 70 million stress repetition? c) Assuming the relationship between "S" and "N" is given by (Hint:GN-K). What will be the N for S 150 MPa? Hint: (Use 1 x10 at 50 MPa and 10 x106 at 100 MPa) S (MPa) 120 110 100 90 80 70 60 50 40 30 20 10 0 1 10 100 1000 N (millions) 10000 100000