(Solved): help me calculate the maximum allowable surface crack length P2. A structural component is fabricat ...

P2. A structural component is fabricated from an alloy that has a plane strain fracture toughness of $40\mathrm{MPa}\sqrt{\mathrm{m}}$. It has been determined that this component fails at a stress of $300\mathrm{MPa}$ when the maximum length of an internal crack is $1.5\mathrm{mm}$. What is the maximum allowable surface crack length (in mm) without fracture for this same component exposed to a stress of $300\mathrm{MPa}$ and made from another alloy with a plane-strain fracture toughness of $60\mathrm{MPa}\sqrt{\mathrm{m}}$ ? (25 points)