Mach to mph

Mach number is the ratio of an object's speed to the speed of sound in the surrounding medium. Mach 1 at 20°C, 1 atm equals approximately 343.6 m/s (1,235 km/h).

Mach = velocity ÷ speed_of_sound. At 20°C: Mach 1 = 343.6 m/s. Speed of sound = √(γRT/M) where γ = heat capacity ratio.

To m/s (at 20°C): × 343.6. To km/h (at 20°C): × 1,237. Note: changes with altitude and temperature.

Fighter jets (Mach 1.5–2.5), commercial aircraft (Mach 0.8–0.85), space shuttle reentry (Mach 25), and missile speeds.

Concorde: Mach 2.04. SR-71 Blackbird: Mach 3.3. X-15: Mach 6.7. Meteorites enter at Mach 50+. Subsonic <1, supersonic >1, hypersonic >5.

Thinking Mach is constant — it varies with temperature/altitude. At 30,000 ft, Mach 1 ≈ 295 m/s (colder air = slower sound).

Mach 1 = speed of sound. Below Mach 1 = subsonic. Mach 1–5 = supersonic. Above Mach 5 = hypersonic. It's a ratio, not a fixed speed.

Mile per hour measures how many statute miles are traveled in one hour. It's the primary speed unit in the United States and some other countries using imperial measurements.

1 mph = 0.44704 m/s = 1.609 km/h. The conversion factor comes from the statute mile definition.

To km/h: × 1.609. To m/s: × 0.447. To ft/s: × 1.467. To knots: × 0.869.

US speed limits (25 mph residential, 65–75 mph interstate), vehicle speeds in US/UK, hurricane wind speeds (74+ mph), and baseball pitch speeds.

Sound barrier: 767 mph at sea level. Fastest car: 282.9 mph (Koenigsegg). Commercial jet: 550–580 mph cruise. Cheetah: 70 mph sprint.

Assuming 1 mph ≈ 1 km/h — actually 1 mph ≈ 1.6 km/h. Also, confusing statute miles with nautical miles.

Quick conversion: multiply mph by 1.6 for approximate km/h. Remember: 60 mph ≈ 100 km/h (slightly off but close).