Answer:
1.44 mm
Explanation:
Compute the maximum allowable surface crack length using
[tex]C=\frac {2E\gamma}{\pi \sigma_c^{2}}[/tex] where E is the modulus of elasticity, [tex]\gamma[/tex] is surface energy and [tex]\sigma_c[/tex] is tensile stress
Substituting the given values
[tex]C=\frac {2\times 393\times 10^{9}\times 0.9}{\pi\times (16\times 10^{6})^{2}= 0.001441103 m\approx 1.44mm[/tex]
The maximum allowable surface crack is 1.44 mm
