Convert Feet per second squared to Miles per hour per second

Convert Feet per second squared (ft/s²) to Miles per hour per second (mph/s) instantly and accurately.

Conversion Formula

mph/s = ft/s² × 0.6818181818

About Feet per second squared

The foot per second squared (ft/s²) equals exactly 0.3048 m/s², the coherent acceleration unit in the imperial engineering system where F [lbf] = m [slug] × a [ft/s²]. Standard gravity is g₀ = 32.174 ft/s², a constant used throughout US aerospace and structural engineering - from legacy NACA reports to modern software (SAP2000, ETABS with US units). A car braking at 0.8 g decelerates at about 25.7 ft/s². 1 ft/s² = 0.3048 m/s² ≈ 3.108 × 10⁻² g₀.

About Miles per hour per second

The mile per hour per second (mph/s) equals exactly 0.44704 m/s², the natural acceleration unit for road vehicles in the US and UK where speed is measured in mph. A 0-60 mph time of 2.0 s (Tesla Model S Plaid) gives 30 mph/s ≈ 13.4 m/s²; a typical family car at 8.5 s gives 7.1 mph/s ≈ 3.2 m/s². Emergency braking for Amtrak trains requires at least 26 mph/s ≈ 11.6 m/s². 1 mph/s = 0.44704 m/s² (exact) ≈ 4.56 × 10⁻² g₀.

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