1. The Hubert H. Humphrey Metrodome in Minneapolis opened in 1982 at a cost of $55 million. To prepare for the footings, et cetera, 3.00x105 cubic yards of dirt were removed. The Metrodome's inflatable roof covers 10.0 acres and its interior volume is 60.0x103 cubic feet. During construction, 40.0x103 cubic yards of concrete, 11.9x103 tons of reinforcing steel, and 5.00x102 tons of structural steel were utilized. The roof material includes an outer layer of Teflon-coated glass and an inner layer of woven fiberglass. Given this information, answer the following: If removed evenly over the 10.0 acres, how deep a hole would be formed as a result of the excavation? yards If the two-layer fiberglass roofing material has a mass of 0.667 lbm/ft2, what is the total mass of the roof? lbm If 10.0 inches of wet snow collected on the roof (this happened in 1982), what is the added mass on the roof? (Assume 1 inch of water equals 10 inches of snow).
2. A waterbed mattress has the following dimensions: 210 cm X 160 cm X 27 cm. The density of water is 62.4lb/ft3. What is the weight of the bed in pounds? lb If the mattress is placed on the floor (no bed frame), how much pressure does it exert on the floor in pounds per square inch?