# Comment: I'm a Mechanical Engineer, and

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### I'm a Mechanical Engineer, and

looking at how the vessel failed, the pressure inside had to be around 1000 psi to cause the actually pot itself to burst, assuming a 12 inch diameter, stainless steel construction and a 1/8" wall thickness.

1000 psi on a 12 diameter inch lid gives you 113,000 lbs of force, and assuming the 1 pound lid accelerates with this force over 1 foot, the lid would be traveling 260 meters per second, or around the speed of sound. Given the size of the expanding cloud, 1 foot is conservative.

Considering the thing is large, flat and lightweight, it will slow down very quickly, and the 100 foot range and 80 foot climb seems reasonable. Aerodynamic drag at high speed is tremendous, just think about how fast spitzer shaped bullets slow down. Translate that to a flat, spinning pressure cooker lid. Also, it could have climbed much higher than 80 feet to have landed on the roof. If it were found on the street, you wouldn't assume it only went one foot in the air.

260m/s is 850fps, like a black powder round, and is consistent with the type of collateral damage caused by the ball bearings.

Author of Shades of Thomas Paine, a common sense blog with a Libertarian slant.