on september 9, 2010, a commercial steel natural gas transmission pipeline, owned and operated by the pacific gas and electric company (PG&E), rupture in san bruno, california, the inside pipe diameter was 30 inches and tha pressure 11.2 km upstream was 400 psia. the temperature was 64 F (524 R) a. estimete the flowrate of natural gas in kg/s under the assumption of a full-bore rupture you may assume that the interior of the pipe could be described as having general rustb. was the flow choked ?