ultrasonic testing of an aircraft engine component revealed maximum internal defects of 3mm length. theses defects will grow under cyclic loading until they become critical in length. given the following information, calculate the size of defect that will result in fast fracture after 100 million cyclic . assume a pairs exponent of 3 , actress amplified of 5 mpa and a material constant , A of 4 x 10^-11?