speed 0acceleration 9.81 m/s²
A falling skydiver feels two forces: weight, which is constant, and air drag, which grows with the square of speed: F = ½·ρ·v²·Cd·A. At first drag is small and they accelerate at nearly g. As speed builds, drag catches up, the net force shrinks, and the speed levels off where drag equals weight: terminal velocity, about 200 km/h belly-down. Opening the canopy multiplies Cd·A about a hundredfold, so drag jumps far above weight and they slow until it balances again at about 5 m/s.