1) A steel cable 1.25 inches in diameter and 50 ft long is to lift a 40,000 lb weight. What is the length of the cable during lifting? The modulus of elasticity of the steel is 30×106 psi.

1)
A steel cable 1.25 inches in diameter and 50 ft long is to lift a 40,000 lb weight. What is the length of the cable during lifting? The modulus of elasticity of the steel is 30×106 psi.
2)
A large flat plate is subjected to constant amplitude uniaxial cyclic tensile and compressive stresses. Compute the critical crack length if the fatigue life must be at least 3×106 cycles. Assume the initial maximum edge surface crack length to be 1.1 mm, and a maximum tensile stress of 160 MPa. Assume m=3.0, A=1.4×10-13MPa in meter units, and Y=1.2.