A brittle material is subjected to a tensile stress of 32MPA. If the specific surface energy is 0.4J/m2 and the modulus of elasticity for the material is 69GPA what is the maximum length of a surface flaw that is possible without fracture? Use equation 8.3 and note that the variable 2a gives us total crack length of an internal crack, so 1/2 of this would give us the length of a surface flaw.
1- 2.57x10^-6m
2- 4.14x10^-2m
3- 1.34x10^-4m
4- 1.715x10-5m