A storage tank has a diameter of 80 ft, a height of 25 feet, and contains oil to a height of 15 ft. The suction pumps, whichcan handle 15, 000 bbl/d are started, but the safety valves areclogged and a vacuum is drawn in the tank. The roof is flatand rated to withstand 1.0 oz/sq in. before collapsing. Thebarometric pressure is 30 in Hg. How long will it take thetank to collapse? What is the total force on the roof atcollapse? How would more oil in the tank have affected the collapse time?