In order to find the terminal velocity, a drag coefficient (Cd) is required. Examples of approximate drag coefficients include: laminar flow on flat plate (0.001), aircraft (0.03), smooth ball (0.1), bullet (0.3), car (0.3), cyclist or skier (1.0), brick (2.1).
The density of air at sea level is ~1.5 kg/m³), and the strength of gravity is 1 g (or 9.80665 m/s²).