What is the expected life 1 inch diameter bar machined from AISI 1020 CD Steel is subjected to alternating bending stress between 1 and 50 kpsi at 350 deg C. Find the factor of safety guarding against static (single cycle) failure, and either the factor of safety guarding against fatigue failure or the expected life of the part with 99 percent reliability.

Ashielded metal arc-welding operation is accomplished in a work cell by a fitter and a welder. the fitter takes 5.5 min to load components into the welding fixture at the beginning of the work cycle, and 1.5 min to unload the completed weldment at the end of the cycle. the total ength of the weld seams 1200 mm, and the travel speed used by the welder averages 300 mm/min. every 600 mm of seam length, the welding stick must be changed, which takes 0.8 min. while the fitter is working, the welder is idle (resting): and while the welder is working the fitter is idle. (a) determine the average arc-on time as a fraction of the work cycle time. (b) how much improvement in arc-on time would result if the welder used flux-cored arc welding (manually operated), given that the spool of weld wire must be changed every 10 weldments, and it takes the welder 5.0 min to accomplish the change? (c) what are the production rates for these two cases (weldments completed per hour)? attach your work and solutions.

Plot schematically the tensile stress versus strain curves for a typical thermoplastic material at a temperature below its glass transition temperature (tg and at a temperature above its tg, respectively. do the same for a typical thermosetting material. list in a table any differences or similarities between the two materials at t> tg and t < tg, respectively, and relate them to the structures of the two types of polymers

At steady state, air enters an insulated duct of varying cross-sectional area (similar to a nozzle or diffuser) at 200 kpa, 52°c with a mass flow rate of 0.5 kg/s. at the duct exit, the pressure of the air is 100 kpa, the velocity is 255 m/s, and the cross-sectional area is 2 x 10-3 m^2. assuming an ideal gas model, determine: a)-find the specific volume of the air at the exit, in m3/kg. b)- the temperature of the air at the exit, in k. c)-the velocity of the air at the inlet, in m/s. d)-the inlet cross-sectional area, in m^2.