Suppose the Boeing 797 fuselage will be made of aluminum 7075 alloy with a yiled strength og 495 Mpa and touhgness of Kc 24 Mpa Vm. The hoop stress on the fuseage is about 150 Mpa due to the relative cabin pressure during flight. EXTERIOR 5.30 m INTERIOR TRIM TO TRM 1. Calculate the critical crack length of a crack that will propogate catastrophically under this amount of stress.