An aircraft component is fabricated from an aluminum alloy that has a plane strain fracture toughness of 32 . It has been determined that fracture results at a stress of 219 MPa when the maximum (or critical) internal crack length is 2.68 mm. a) Determine the value of for this same component and alloy at a stress level of 284 MPa when the maximum internal crack length is 1.34 mm.

Adouble-strand no. 60 roller chain is used to transmit power between a 13-tooth driving sprocket rotating at 300 rev/min and a 52-tooth driven sprocket. a) what is the allowable horsepower of this drive? b) estimate the center-to-center distance if the chain length is 82 pitches. c) estimate the torque and bending force on the driving shaft by the chain if the actual horsepower transmitted is 30 percent less than the corrected (allowable) power.

Starting wih an energy balance on a rectangular volume element, derive the one- dimensional transient heat conduction equation for a plane wall with constant thermal conductivity and no heat generation.

Technician a says that in a worm gear steering system, most excessive steering free play is usually found in the gearbox. technician b says that in a rack-and-pinion steering system, excessive free play can be found in the bushings. who is correct?