An AISI 1040 cold-drawn steel tube has an OD = 50 mm and wall thickness 6 mm. What maximum external pressure can this tube withstand if the largest principal normal stress is not to exceed 80 percent of the minimum yield strength of the material?

Consider airflow over a flat plate of length l = 1.5 m under conditions for which transition occurs at le = 0.9 m based on the critical reynolds number, re,e = 5 x 10. evaluating the thermophysical properties of air at 400 k, determine the air velocity. (hint: use the tables to find the properties of air)