A square tank 12 feet high having a perimeter of 40 feet is filled with water weighing 62.4 pounds per cubic foot. The total horizontal force on one side of the tank due to the water pressure is MOST NEARLY ________ pounds. A. 58,000 B. 45,000 C. 36,000 D. 13,000 The answer key says 45,000 lbs. is the answer but I have no clue how they got there. Total pressure - lbs./ft^2 - should be 12 x 62.4, or 5.2lbs/in^2. How do they get 45,000?