Convert Feet per Minute to Mach 20
Convert Feet per Minute (ft/min) to Mach 20 (Ma20) instantly and accurately.
Conversion Formula
Ma20 = ft/min × 7.464221693e-7
About Feet per Minute
A foot per minute (ft/min) = 5.08 × 10⁻³ m/s - the US standard for elevator speed, HVAC duct velocity, and conveyor speed. Residential lifts: 100-200 ft/min; commercial 200-400 ft/min; skyscraper express lifts 1,000-3,000 ft/min (Burj Khalifa 2,953 ft/min). HVAC low-velocity ductwork: 500-1,000 ft/min; medium-velocity 1,000-2,200 ft/min. Paper machine Fourdrinier wires: 200-6,000 ft/min. 1 ft/min = 0.00508 m/s.
About Mach 20
Mach 20 ≈ 6,805.8 m/s (24,501 km/h) at ISA sea level - the peak heating regime of ballistic re-entry. Shock layer temperature exceeds 10,000 K; plasma sheath causes radio blackout. Space Shuttle decelerated through Mach 20 at ~75-80 km altitude; Apollo CM hit the atmosphere at ~Mach 36; ICBM warheads re-enter at Mach 18-24. DARPA HTV-2 reached Mach 20 in 2011. 1 Mach 20 = 6,805.8 m/s.
Quick Reference Table
| Feet per Minute (ft/min) | Mach 20 (Ma20) |
|---|---|
| 1 ft/min | 7.464 × 10-7 Ma20 |
| 2 ft/min | 1.493 × 10-6 Ma20 |
| 5 ft/min | 3.732 × 10-6 Ma20 |
| 10 ft/min | 7.464 × 10-6 Ma20 |
| 25 ft/min | 1.866 × 10-5 Ma20 |
| 50 ft/min | 3.732 × 10-5 Ma20 |
| 100 ft/min | 7.464 × 10-5 Ma20 |