Repeat Prob. 3101 with an internal pressure. Repeat Prob. 3101, An AISI 1040 cold-drawn steel tube has

Question:

Repeat Prob. 3–101 with an internal pressure.
Repeat Prob. 3–101, 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?