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.
Terminal velocity of a 5 kg box with 0.09 m² frontal area
Answer: terminal velocity = 29.11 m/s (terminal velocity 104.8 km/h).
What we know
- Mass: 5 kg
- Drag coefficient: 1.05
- Cross-sectional area: 0.09 m²
- Air density: 1.225 kg/m³
Cd 1.05 is the textbook value for a cube face-on.
Step by step
- Given
- m = 5 kg, Cd = 1.05, A = 0.09 m², ρ = 1.225 kg/m³
- Formula
- v = √(2mg / (ρ·A·Cd))
- Substitute
- v = √(2 × 5 × 9.80665 / (1.225 × 0.09 × 1.05))
- Result
- v = 29.11 m/s
All results
| Terminal velocity | 29.11 m/s |
|---|---|
| Terminal velocity | 104.8 km/h |
Open the terminal velocity calculator with these numbers → and change any of them.