The physics
Terminal velocity is the speed at which air drag exactly balances gravity, so a falling object stops accelerating. Drag grows with the square of speed, so every falling object eventually finds this equilibrium.
Descent speed of 90 kg under a 30 m² parachute
Answer: terminal velocity = 5.66 m/s (terminal velocity 20.4 km/h).
What we know
- Mass: 90 kg
- Drag coefficient: 1.5
- Cross-sectional area: 30 m²
- Air density: 1.225 kg/m³
Drag coefficient of 1.5 assumed for a round canopy.
Step by step
- Given
- m = 90 kg, Cd = 1.5, A = 30 m², ρ = 1.225 kg/m³
- Formula
- v = √(2mg / (ρ·A·Cd))
- Substitute
- v = √(2 × 90 × 9.80665 / (1.225 × 30 × 1.5))
- Result
- v = 5.66 m/s
All results
| Terminal velocity | 5.66 m/s |
|---|---|
| Terminal velocity | 20.4 km/h |
Open the terminal velocity calculator with these numbers → and change any of them.