Asolid round bar with diameter of 50-mm has a groove cut to a diameter of 45-mm, with a radius of 2.5-mm. the bar is not rotating. the bar is loaded with a repeated bending load that causes the bending moment at the groove to fluctuate between 0 and 2825 n-m. the bar is hot-rolled aisi 1095, but the groove has been machined. a) determine the factor of safety for fatigue based on infinite life and b) determinethe factor of safety for yielding.

Acommercial grade cubical freezer, 4 m on a side, has a composite wall consisting of an exterior sheet of 5.0-mm thick plain carbon steel (kst= 60.5 w/m k), an intermediate layer of 100-mm thick polyurethane insulation (kins 0.02 w/m k), and an inner sheet of 5.0- mm thick aluminium alloy (kal polyurethane insulation and both metallic sheets are each characterized by a thermal contact resistance of r 2.5 x 104 m2 k/w. (a) what is the steady-state cooling load that must be maintained by the refrigerator under conditions for which the outer and inner surface temperatures are 25°c and -5°c, respectively? (b) for power saving purpose, which wall material should be increased/reduced in. thickness in order to reduce 50% of the cooling load found in part (a)? redesign the thickness of the proposed material. 177 w/m-k). adhesive interfaces between the q=575.93 w

In the winter, in order to keep the classroom steadily at 68 f before 10 pm, heating with an average rate of 42,000 btu/hr is provided. assume the outdoor temperature maintains at 32°f, determine the electrical power (kw) required to (a) operate a reversible heat pump (b) operate a real heat pump with a cop (7) of 4.5 and (c) operate an electrical-resistance heater.

A5 kg block of fe is dropped into a very large vat of water. the fe and water initial temperatures are 95 and 25 c, respectively. the fe final temperature is 25 c and the water can be treated as a thermal reservoir,. treated as a thermal reservoir take the water to be the system and determine the entropy generation. report vour answer in kj/k.