Knots to Feet Per Second
Converter

Conversion Table

How to convert

1 knot (kt) = 1.687809858 foot per second (fps). Knot (kt) is a unit of Speed used in Standard system. Foot Per Second (fps) is a unit of Speed used in Standard system.

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

Feet per second: A unit of speed

Feet per second (ft/s) is a unit of speed or velocity in the US customary and imperial systems. It measures how fast an object is moving by calculating the distance traveled in feet divided by the time taken in seconds. For example, if a person walks 10 feet in 2 seconds, their speed is 5 ft/s.

How to convert feet per second

Feet per second can be converted to other units of speed or velocity by using simple conversion factors. Here are some common units and their conversion factors:

• Meters per second (m/s): To convert from ft/s to m/s, multiply by 0.3048. To convert from m/s to ft/s, divide by 0.3048. For example, 1 ft/s is equal to 0.3048 m/s, and 10 m/s is equal to 32.8084 ft/s.
• Kilometers per hour (km/h): To convert from ft/s to km/h, multiply by 1.09728. To convert from km/h to ft/s, divide by 1.09728. For example, 1 ft/s is equal to 1.09728 km/h, and 50 km/h is equal to 45.8734 ft/s.
• Miles per hour (mph): To convert from ft/s to mph, multiply by 0.681818. To convert from mph to ft/s, divide by 0.681818. For example, 1 ft/s is equal to 0.681818 mph, and 30 mph is equal to 44 ft/s.
• Knots (kn): To convert from ft/s to kn, multiply by 0.592484. To convert from kn to ft/s, divide by 0.592484. For example, 1 ft/s is equal to 0.592484 kn, and 15 kn is equal to 25.3281 ft/s.
• Inches per second (in/s): To convert from ft/s to in/s, multiply by 12. To convert from in/s to ft/s, divide by 12. For example, 1 ft/s is equal to 12 in/s, and 20 in/s is equal to 1.66667 ft/s.
• Miles per second (mi/s): To convert from ft/s to mi/s, multiply by 0.000189394. To convert from mi/s to ft/s, divide by 0.000189394. For example, 1 ft/s is equal to 0.000189394 mi/s, and 1 mi/s is equal to 5280 ft/s.

Where feet per second are used

Feet per second are mainly used in engineering and aviation to measure the speed or velocity of machines and aircrafts.

For example, the speed of sound in air at sea level is about 343 m/s or about 1125 ft/s.

The maximum speed of a Boeing 747 jet airliner is about 988 km/h or about 2717 ft/s.

The average speed of a bullet fired from a handgun is about 1200 ft/s.

Definition of feet per second

According to the US customary and imperial systems definition, one foot per second is the speed of a body that covers a distance of one foot in a time of one second.

Mathematically, it can be expressed as:

v = s / t

where v is the speed or velocity in feet per second, s is the distance traveled in feet, and t is the time taken in seconds.

History of feet per second

The concept of speed or velocity has been studied since ancient times by philosophers and scientists such as Aristotle, Galileo, Newton, etc.

The foot was originally derived from the Roman foot which was defined as one third of a yard or about 11.65 inches.

The second was originally defined in terms of the Earth’s rotation as one eighty-six thousand four hundredth of a mean solar day.

The combination of these two units resulted in the foot per second as a unit of speed or velocity.

The foot per second was officially adopted as part of the US customary and imperial systems in the late 18th century.

Example conversions of feet per second to other units

Here are some examples of converting feet per second to other units of speed or velocity:

1 ft/s = 0.3048 m/s = 1.09728 km/h = 0.681818 mph = 0.592484 kn = 12 in/s = 0.000189394 mi/s
2 ft/s = 0.6096 m/s = 2.19456 km/h = 1.36364 mph = 1.18497 kn = 24 in/s = 0.000378788 mi/s
5 ft/s = 1.524 m/s = 5.4864 km/h = 3.40909 mph = 2.96241 kn = 60 in/s = 0.00094697 mi/s
10 ft/s = 3.048 m/s = 10.9728 km/h = 6.81818 mph = 5.92482 kn = 120 in/s = 0.00189394 mi/s
20 ft/s = 6.096 m/s = 21.9456 km/h = 13.6364 mph = 11.8496 kn = 240 in/s = 0.00378788 mi/s
50 ft/s = 15.24 m/s = 54.864 km/h = 34.0909 mph = 29.6241 kn = 600 in/s = 0.0094697 mi/s
100 ft/s = 30.48 m/s = 109.728 km/h = 68.1818 mph = 59.2482 kn = 1200 in/s = 0.0189394 mi/s