building is to be designed to withstand hurricane-force winds. The maximum wind velocity is v=89 ms. The surface area of the roof is A=450m . If the density of air is ρ=1.027kgm3 , how much force must the roof supports be able to withstand?

A 2.5-m-tall steel cylinder has a cross-sectional area of 1.5 m2. At the bottom, with a height of 0.5 m, is liquid water, on top of which is a 1-m high layer of gasoline, relative density of 0.8. The gasoline surface is exposed to atmospheric air at 101 kPa. What is the total mass of the liquid in the cylinder? 2000 kg O 1250 kg O 3250 kg O 1625 kg

A frequently quoted rule of thumb in aircraft design is that wings should produce about 1000 N of lift per square meter of wing. (The fact that a wing has a top and bottom surface does not double its area.) a. At takeoff, an aircraft travels at 54 m/s, so that the air speed relative to the bottom of the wing is 54 m/s. Given the sea level density of air to be 1.29 kg/m^3, how fast must it move over the upper surface to create the ideal lift? b. How fast must air move over the upper surface at a cruising speed of 242 m/s and at an altitude where air density is one-fourth that at sea level?

Dr. B uses his phone and the app phyphox to measure atmospheric pressure at different heights. At the first floor of the UMass W.E.B. DuBois Library he measures a pressure of 101300 Pa. He then takes the elevator to the roof of the library and measures a pressure of 100172 Pa. If the density of the air is 1.205kg/m33, what is the height of the library? a. 124 m b. 96 m c. 76 m d. 67 m e. 105 m