Please include a stepbystep solution thats clear and PLEASE

Please include a step-by-step solution thats clear and PLEASE circle your finals answers. :)

The options to part C are:

i) 0 ii) 20000 iii) 50000 iv) an infinite number

Solution

a) from the fig, fatigue limit = 290 MPa

b) from the fig, fatigue lifetime at 440 MPa = 2.5x10⁴ cycles

c) from the fig, fatigue lifetime at 280 MPa = 0 (option A)

d) from the fig, fatigue strength at 6x10⁵ cycles = 345 MPa (approx.)