Convert Furlong per Fortnight to Mach 5
Convert Furlong per Fortnight (fur/fn) to Mach 5 (Ma5) instantly and accurately.
Conversion Formula
Ma5 = fur/fn × 9.774576027e-8
About Furlong per Fortnight
A furlong per fortnight (fur/fn) is a deliberately archaic unit equal to exactly 201.168 ÷ 1,209,600 m/s ≈ 1.663 × 10⁻⁴ m/s - just slightly faster than a garden snail at full creep. One furlong (one-eighth of a mile = 201.168 m) and one fortnight (14 days = 1,209,600 s) are both perfectly legitimate historical measures, but their combination is cherished in physics teaching as a cautionary example of needlessly exotic unit choices. Expressing kinetic energy in kg·fur²/fn² or force in kg·fur/fn² illustrates instantly why the SI was universally adopted. The unit appears in satirical physics papers, recreational mathematics columns, and Terry Pratchett's Discworld novels as the native velocity unit of magical phenomena. The speed of light expressed in furlongs per fortnight is approximately 1.803 × 10¹² fur/fn. Snails travel at roughly 0.5-1 fur/fn; strong tidal rip currents reach 100-200 fur/fn. 1 fur/fn ≈ 1.663 × 10⁻⁴ m/s ≈ 0.599 km/h ≈ 0.372 mph.
About Mach 5
Mach 5 ≈ 1,701.45 m/s (6,125 km/h) at ISA sea level - the conventional supersonic/hypersonic boundary. Above Mach 5, stagnation temperatures exceed 1,500°C, air dissociates around the vehicle, and ablative thermal protection becomes mandatory. Space Shuttle re-entered at Mach 25; Soyuz capsules at Mach 27; ICBM warheads at Mach 15-25. NASA X-43A scramjet reached Mach 9.6 (air-breathing record, 2004). 1 Mach 5 = 1,701.45 m/s.
Quick Reference Table
| Furlong per Fortnight (fur/fn) | Mach 5 (Ma5) |
|---|---|
| 1 fur/fn | 9.775 × 10-8 Ma5 |
| 2 fur/fn | 1.955 × 10-7 Ma5 |
| 5 fur/fn | 4.887 × 10-7 Ma5 |
| 10 fur/fn | 9.775 × 10-7 Ma5 |
| 25 fur/fn | 2.444 × 10-6 Ma5 |
| 50 fur/fn | 4.887 × 10-6 Ma5 |
| 100 fur/fn | 9.775 × 10-6 Ma5 |