1. An 8-cm sphere is tested in 30°C water flowing at 5 m/s, yields a measured drag of 12 N. For a 2.875-m weather balloon moving in air at 7°C and one atmosphere, determine the velocity and drag force.
2. Is it reasonable to use air in a subsonic wind tunnel at the same temperature and pressure for a test to find the drag on a 1:24 scale model of an aircraft whose velocity is 4.5 km/h.