When designing a building, you must be sure that the building can withstand hurricane force winds, which have a velocity of 73mi/h or more. The formula f = 0.004av2 gives the force f in pounds exerted by a wind blowing against a flat surface. A is the area of the surface in square feet and v is the wind velocity in miles per hour. How much force is exerted by a wind blowing at 81 mi/h against the side of the building shown?