Mach to Knots
Converter

Conversion Table

How to convert

1 mach (M) = 661.4631565 knot (kt). Mach (M) is a unit of Speed used in Metric system. Knot (kt) is a unit of Speed used in Standard system.

Mach number

Definition of Mach

Mach, commonly denoted M or Ma, is a dimensionless quantity in fluid dynamics representing the ratio of flow velocity past a boundary to the local speed of sound. It is named after the Austrian physicist and philosopher Ernst Mach, who studied gas dynamics and shock waves. Mach number is used to classify the flow regimes based on the effects of compressibility and shock waves on the flow.

How to Convert Mach

To convert mach to other units of speed, we need to multiply by the local speed of sound in the medium, which depends on the temperature and pressure of the gas. For example, to convert mach to meters per second, we need to multiply by the speed of sound in air at sea level, which is about 340 m/s. To convert mach to kilometers per hour, we need to multiply by the speed of sound in air at sea level and by 3.6, since there are 3.6 seconds in one hour.

Here are some examples of how to convert mach to other units of length in the US Standard system and the SI system:

• To convert 1 M to meters per second (m/s), we multiply by 340: 1 M x 340 = 340 m/s
• To convert 2 M to kilometers per hour (km/h), we multiply by 340 and by 3.6: 2 M x 340 x 3.6 = 2448 km/h
• To convert 3 M to miles per hour (mph), we multiply by 340 and by 2.2369362920544, since there are 2.2369362920544 miles in one kilometer: 3 M x 340 x 2.2369362920544 = 2285.714285714 mph
• To convert 4 M to feet per second (fps), we multiply by 340 and by 3.2808398950131, since there are 3.2808398950131 feet in one meter: 4 M x 340 x 3.2808398950131 = 4465.306122449 fps
• To convert 5 M to knots (kn), we multiply by 340 and by 1.9438444924406, since there are 1.9438444924406 nautical miles in one kilometer: 5 M x 340 x 1.9438444924406 = 3316.326530612 kn
• To convert 6 M to centimeters per second (cm/s), we multiply by 340 and by 100, since there are 100 centimeters in one meter: 6 M x 340 x 100 = 204000 cm/s

Where Mach Is Used

Mach is used in various fields of science and technology where the speed and direction of movement of objects or phenomena are measured or applied in relation to the speed of sound in the medium. For example:

• In aerodynamics and aeronautics, mach is used to measure the speed and performance of aircraft, rockets, missiles, and other flying vehicles, as well as the effects of air resistance, drag, lift, and thrust on them.
• In acoustics and sound engineering, mach is used to measure the intensity and frequency of sound waves, as well as the effects of reflection, refraction, diffraction, interference, and Doppler shift on them.
• In meteorology and climatology, mach is used to measure the speed and direction of wind, storms, hurricanes, tornadoes, and other weather phenomena, as well as the effects of temperature, pressure, humidity, and density on them.

History of Mach

The concept of mach number was first introduced by Swiss engineer Jakob Ackeret in his doctoral thesis in 1929. He proposed it as a convenient way to express the ratio of flow velocity to speed of sound in gas dynamics problems. He also named it after Ernst Mach, who had conducted experiments on supersonic projectiles and shock waves in the late nineteenth century.

The term mach number was later popularized by German-American engineer Theodore von Karman, who used it extensively in his research on aerodynamics and supersonic flight in the early twentieth century. He also established the first supersonic wind tunnel at Caltech in 1939.

The first human-made object to break the sound barrier was a rocket-powered plane called Bell X-1 piloted by Chuck Yeager in October 1947. He achieved a speed of about Mach 1.06 at an altitude of 13,000 meters.
The first human to travel faster than sound was Soviet cosmonaut Yuri Gagarin, who orbited the Earth at a speed of about Mach 25 in April 1961.
The fastest manned aircraft ever flown was the North American X-15, which reached a speed of about Mach 6.7 in October 1967.

The fastest unmanned aircraft ever flown was the NASA X-43A, which reached a speed of about Mach 9.6 in November 2004.

Example Conversions of Mach to Other Units

Here are some examples of how to convert mach to other units of speed, using the conversion factors given above:

• To convert 1 M to meters per second, we multiply by 340: 1 M x 340 = 340 m/s
• To convert 2 M to kilometers per hour, we multiply by 340 and by 3.6: 2 M x 340 x 3.6 = 2448 km/h
• To convert 3 M to miles per hour, we multiply by 340 and by 2.2369362920544: 3 M x 340 x 2.2369362920544 = 2285.714285714 mph
• To convert 4 M to feet per second, we multiply by 340 and by 3.2808398950131: 4 M x 340 x 3.2808398950131 = 4465.306122449 fps
• To convert 5 M to knots, we multiply by 340 and by 1.9438444924406: 5 M x 340 x 1.9438444924406 = 3316.326530612 kn
• To convert 6 M to centimeters per second, we multiply by 340 and by 100: 6 M x 340 x 100 = 204000 cm/s
• To convert 7 M to millimeters per minute, we multiply by 340 and by 1000, since there are 1000 millimeters in one meter, and multiply by 60, since there are 60 minutes in one hour: 7 M x 340 x 1000 x 60 = 142800000 mm/min

Knots

Definition of Knots

Knots, commonly denoted kn, is a unit of speed equal to one nautical mile per hour, exactly 1.852 km/h (approximately 1.151 mph or 0.514 m/s). It is the standard unit of speed used in meteorology, and in maritime and air navigation. A vessel travelling at 1 kn along a meridian travels approximately one minute of geographic latitude in one hour.

How to Convert Knots

To convert knots to other units of speed, we need to multiply or divide by the corresponding conversion factors. For example, to convert knots to kilometers per hour, we need to multiply by 1.852, since there are 1.852 kilometers in one nautical mile. To convert knots to meters per second, we need to divide by 3.6, since there are 3.6 seconds in one hour.

Here are some examples of how to convert knots to other units of length in the US Standard system and the SI system:

• To convert 10 kn to kilometers per hour (km/h), we multiply by 1.852: 10 kn x 1.852 = 18.52 km/h
• To convert 20 kn to miles per hour (mph), we multiply by 1.1507794480235, since there are 1.1507794480235 miles in one nautical mile: 20 kn x 1.1507794480235 = 23.01558896047 mph
• To convert 30 kn to feet per second (fps), we multiply by 1.6878098571012, since there are 1.6878098571012 feet in one meter: 30 kn x 1.6878098571012 = 50.634295713036 fps
• To convert 40 kn to meters per second (m/s), we divide by 3.6: 40 kn / 3.6 = 11.111111111111 m/s
• To convert 50 kn to meters per minute (m/min), we multiply by 60, since there are 60 minutes in one hour: 50 kn x 60 = 3,000 m/min
• To convert 60 kn to centimeters per second (cm/s), we multiply by 100, since there are 100 centimeters in one meter, and divide by 3.6: 60 kn x 100 / 3.6 = 5,000 cm/s

Where Knots Are Used

Knots are used in various fields of science and technology where the speed and direction of movement of objects or phenomena are measured or applied in relation to water or air currents. For example:

• In meteorology, knots are used to measure wind speed and direction, as well as the speed and direction of storms, hurricanes, and other weather phenomena.
• In maritime navigation, knots are used to measure the speed and direction of ships, boats, submarines, and other watercraft, as well as the speed and direction of ocean currents, tides, and waves.
• In air navigation, knots are used to measure the speed and direction of aircraft, helicopters, rockets, satellites, and other aerospace vehicles, as well as the speed and direction of air currents, jet streams, and wind shear.

History of Knots

The origin of knots as a unit of speed can be traced back to the ancient practice of measuring the speed of ships by using a device called a chip log or log-line. This device consisted of a wooden board attached to a rope with knots tied at regular intervals along its length. The board was thrown overboard from the stern of the ship and allowed to drag behind it while the rope was let out for a fixed amount of time (usually measured by a sandglass). The number of knots that passed over the rail of the ship during that time indicated the speed of the ship in nautical miles per hour.

The first recorded use of this method was by the Phoenicians around the second millennium BCE. The device was later improved and standardized by various civilizations such as the Greeks, Romans, Arabs, Vikings, Chinese, and Europeans. The length of the nautical mile and the spacing of the knots varied from place to place and from time to time until they were fixed by international agreement in the late nineteenth century.

The term knot was derived from the Old English word cnotta meaning “a knot”. It was first used as a unit of speed by English sailors in the early seventeenth century.

Example Conversions of Knots to Other Units

Here are some examples of how to convert knots to other units of speed, using the conversion factors given above:

• To convert 100 kn to kilometers per hour, we multiply by 1.852: 100 kn x 1.852 = 185.2 km/h
• To convert 200 kn to miles per hour, we multiply by 1.1507794480235: 200 kn x 1.1507794480235 = 230.15589792094 mph
• To convert 300 kn to feet per second, we multiply by 1.6878098571012: 300 kn x 1.6878098571012 = 506.34295713011 fps
• To convert 400 kn to meters per second, we divide by 3.6: 400 kn / 3.6 = 111.11111111111 m/s
• To convert 500 kn to meters per minute, we multiply by 60: 500 kn x 60 = 30,000 m/min
• To convert 600 kn to centimeters per second, we multiply by 100 and divide by 3.6: 600 kn x 100 / 3.6 = 50,000 cm/s
• To convert 700 kn to millimeters per minute, we multiply by 1000, since there are 1000 millimeters in one meter, and multiply by 60: 700 kn x 1000 x 60 = 42,000,000 mm/min