Cylindrical pylons are used to define an entrance to a new hotel. inside the tubular pylons are lights to illuminate the hotel entrance at night. the designer needs to consider taxis, automobiles, and delivery trucks hitting these pylons. the outer diameter d of the pylons is 10 in and the wall thickness t 0.25 in determine the maximum stress in the pylon if a "vehicle" hits a pylon at 18 in above ground. what is the maximum g-force on the chauffeur of the vehicle?