in which F=total drag or force on the object;Cd, CL = drag (d), lift (L)coefficient for the object; q = dynamic pressure; and A = projected area perpendicular to the air flow for drag, or parallel to the air flow for lift. Drag and lift coefficients for various structural shapes of infinite length are shown in FIg. 4.2. The data are for overpressures less than 20 psi (140kPa). For higher pressures, the drag coefficients can be adjusted by using the results of a long plate tested in a free air flow. The drag coefficient for the long plate increases from a value of 2.0 at an overpressure of 20 psi (140kPa) to a value of2.5 at approximately 60 pSI (410kPa), and drops to 1.8 at approximately 300 psi (2,100 kPa). .