A rectangular shaped sign is being designed for advertisements on the coast of South Carolina. The...

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A rectangular shaped sign is being designed for advertisements on the coast of South Carolina. The advertising agency needs twenty, 25 ft x 15 ft signs that stand 40 feet in height. Determine the drag force on the sign for wind speeds of 50, 70, 90, 110 and 130 mph. List possible solutions to reduce drag force. Any concerns about the post that supports the sign? What is the moment at the bottom of the post? Useful information: Mass density of air = 0.00237 slug/ft³ Drag coefficient of rectangular sign = 1.15 Cars have several factors to overcome to improve their fuel economy. Two are work done against rolling friction and work done to overcome aerodynamic drag. Prior to purchasing your next car, you wonder if the drag coefficient makes a difference on fuel consumption. The Volkswagen XL1 has a Ca of 0.19 and a frontal area of 11.0 square feet, one of the lowest on the market. Compare with a typical car that has a Ca of 0.30 and a frontal area of 20 square feet. Assumptions: 1 US gallon of gasoline has 125,000 BTU's of energy. Efficiency of engine: 30%. Average miles driven per year: 15,000 miles Average speed: 60 mph Fuel cost: $/gallon. Mass density of air: 0.00237 slug/ft³ A rectangular shaped sign is being designed for advertisements on the coast of South Carolina. The advertising agency needs twenty, 25 ft x 15 ft signs that stand 40 feet in height. Determine the drag force on the sign for wind speeds of 50, 70, 90, 110 and 130 mph. List possible solutions to reduce drag force. Any concerns about the post that supports the sign? What is the moment at the bottom of the post? Useful information: Mass density of air = 0.00237 slug/ft³ Drag coefficient of rectangular sign = 1.15 Cars have several factors to overcome to improve their fuel economy. Two are work done against rolling friction and work done to overcome aerodynamic drag. Prior to purchasing your next car, you wonder if the drag coefficient makes a difference on fuel consumption. The Volkswagen XL1 has a Ca of 0.19 and a frontal area of 11.0 square feet, one of the lowest on the market. Compare with a typical car that has a Ca of 0.30 and a frontal area of 20 square feet. Assumptions: 1 US gallon of gasoline has 125,000 BTU's of energy. Efficiency of engine: 30%. Average miles driven per year: 15,000 miles Average speed: 60 mph Fuel cost: $/gallon. Mass density of air: 0.00237 slug/ft³