What is mach (approx at sea level)?
Mach is a dimensionless speed unit expressing the ratio of an object’s speed to the local speed of sound. At sea level, Mach 1 is approximately 343 m/s. It is used in aviation and aerodynamics to characterise high-speed flight regimes.
Real-world uses
Mach numbers are used in aerospace engineering and aviation to describe aircraft speed relative to the speed of sound. Commercial jets cruise near Mach 0.85, military fighters reach Mach 2+, and hypersonic vehicles exceed Mach 5.
History
Named after Austrian physicist Ernst Mach, who studied supersonic projectiles in the 1880s. The Mach number was formally defined by Swiss engineer Jakob Ackeret in 1929. Chuck Yeager first broke the sound barrier (Mach 1) in 1947 in the Bell X-1.
Common mistakes
Treating Mach as a fixed speed—it varies with altitude and temperature because the speed of sound changes. Mach 1 is about 343 m/s at sea level (15°C) but about 295 m/s at 11,000 m altitude.
What is centimetre per second?
Centimetre per second is a unit of speed used in low-velocity applications such as biological locomotion studies, microfluidics research, and slow-moving mechanical systems.
Real-world uses
Centimetres per second is used in the CGS system for fluid flow rates, sedimentation velocities in geology, and blood flow measurements in medical Doppler ultrasound. Glacier movement and tectonic plate motion are sometimes expressed in cm/s or cm/year.
History
Centimetres per second was the standard velocity unit in the CGS (centimetre-gram-second) system, widely used in physics until the mid-20th century. While SI uses m/s, cm/s persists in certain scientific fields, particularly fluid mechanics and geophysics.
Common mistakes
Confusing cm/s with m/s by forgetting the factor-of-100 difference. Also, assuming cm/s is too small for practical use—blood flow in major arteries is typically 10–40 cm/s, which is a very practical range.
When is this conversion used?
Converting mach (approx at sea level) to centimetre per second is useful in the speed domain when comparing values across different measurement standards or applying formulas that require a specific unit.
Worked examples
1 mach (approx at sea level) = 34,029 centimetre per second
1 centimetre per second = 0.01 metre per second
How to convert mach (approx at sea level) to centimetre per second
To convert mach (approx at sea level) to centimetre per second, multiply the value by 34,029.
To convert centimetre per second back to mach (approx at sea level), multiply by 0.00002939.
Measurement standards
The SI unit of speed is metres per second (m/s), a derived unit requiring no independent definition. The knot is defined as exactly one nautical mile (1,852 metres) per hour and is sanctioned for maritime and aeronautical navigation by the International Civil Aviation Organization.
Did you know?
The fastest human-made object is the Parker Solar Probe, which reached 635,266 km/h (about 176 km/s) in 2024 during a close pass of the Sun — fast enough to travel from New York to Tokyo in under a minute.
Quick reference: mach (approx at sea level) to centimetre per second
| mach (approx at sea level) | centimetre per second |
|---|---|
| 0.1 | 3,402.9 |
| 0.5 | 17,014.5 |
| 1 | 34,029 |
| 2 | 68,058 |
| 5 | 170,145 |
| 10 | 340,290 |
| 25 | 850,725 |
| 50 | 1,701,450 |
| 100 | 3,402,900 |
| 250 | 8,507,250 |
| 500 | 17,014,500 |
| 1,000 | 34,029,000 |
Common values
| mach (approx at sea level) | centimetre per second | |
|---|---|---|
| Walking speed | 0.00411414 mach (approx at sea level) | 140 centimetre per second |
| City speed limit | 0.04084751 mach (approx at sea level) | 1,390 centimetre per second |
| Highway driving | 0.09198037 mach (approx at sea level) | 3,130 centimetre per second |
| Commercial aircraft | 0.73466749 mach (approx at sea level) | 25,000 centimetre per second |
| Speed of sound (sea level) | 1 mach (approx at sea level) | 34,029 centimetre per second |
Available Speed units
More mach (approx at sea level) conversions
- Convert mach (approx at sea level) to metre per second
- Convert mach (approx at sea level) to kilometre per hour
- Convert mach (approx at sea level) to mile per hour
- Convert mach (approx at sea level) to knot
- Convert mach (approx at sea level) to foot per second
- Convert mach (approx at sea level) to metre per minute
- Convert mach (approx at sea level) to kilometre per second
- Convert mach (approx at sea level) to centimetre per second
- Convert mach (approx at sea level) to mile per minute
Assumption: Mach uses an approximate sea-level reference (about 340.29 m/s).