7. If the radius to the thickness of a pressure vessel is great than 10 then it is a thin-walled pressure vessel ( T or F ) a. In a thin-walled pressure vessel the hoop stress (sometimes called as the circumferential stress) is equal to and the longitudinal stress is where, p,r and t are respectively. b. Express the units of stress in the metric system. What will be the units for pressure, thickness and radius