Respuesta :
Answer:
Answer for the question is given in the attachment.
Explanation:

Answer:
The minimum length of a surface crack that will lead to fracture is 18.16 mm
Explanation:
The critical flaw size is
[tex]a_{c} =\frac{1}{\pi } (\frac{K_{c} }{oY} )^{2}[/tex]
where
Kc = plane strain fracture toughness = 82.4 MPa√m
o = imposed stress = 345 MPa
Y = dimensionless parameter = 1
Replacing
[tex]a_{c} =\frac{1}{\pi } (\frac{82.4}{1*345} )^{2} =18.16x10^{-3} m=18.16mm[/tex]