in boat speed where did the term Knot come from and why is it different MPH?

Answer 1

one knot or nautical mile is equal 1.15 mile. I also think the name know came from how boats used to check their speed. They would throw a weighted rope that had knots equally spaced in to the water. An allotted time would go by and they would count how many knots went through their fingers. Hence giving them their speed in knots.

Answer 2

1 knot = 1 nautical mile/hour = 1.852 km·h−1 exactly. This is based on the internationally agreed length of the nautical mile, as adopted by the US in 1954, the UK in 1970 and other countries. This is the definition used in most, if not all, modern circumstances. Knot is sometimes mistakenly used to refer to the nautical mile itself, but this is incorrect.

The speed of a vessel relative to the fluid itself, and not land, is referred to as 'boat speed' or, for aircraft, 'air speed' and is usually measured in knots. If the medium is flowing, this differs from the ground velocity by the velocity of the medium. Velocity made good refers to ground velocity and may also be expressed in knots in navigation.


Conversions
1 knot is roughly equivalent to:

101.268591 foot/minute
1.687810 foot/second
0.5144444 metres per second (m·s−1)
1.852 kilometres per hour (km·h−1) (exact)
1.150779 mile (statute)/hour (mph)

Origin
In some sailing ships, speed was measured by casting the chip log from the stern. The log was relatively immobile, and attached by line to a reel. Some sources suggest that knots placed at a distance of 47 feet 3 inches (14.4018 m) passed through a sailor's fingers, while another used a 28 second sandglass to time the operation. The knot count would be reported and used in the sailing master's dead reckoning and navigation. This method gives a value for the knot of 20.25 in/s, or 1.85166 km·h−1. The difference from the accepted value today is a bit less than 0.02 %.
And there you have it. The miles called MP/H are based on the shorter Statute Mile.

Answer 3

Robert R and Bersie are closest; a rope with knots in it at aprecise disatnce would have a piece of wood on the end ( the log); the log would be thrown over and the number of knots than ran out over 28 seconds would be the boats speed in knots.....NEVER knots per hour! I'd just like to add that a nautical mile is based on the circumference of the planet Earth. If you were to cut the Earth in half at the equator, you could pick up one of the halves and look at the equator as a circle. You could divide that circle into 360 degrees. You could then divide a degree into 60 minutes. A minute of arc on the planet Earth is 1 nautical mile.hence the phrase , a mile a minute.
An US or English mile is 5,280 feet and I am NOT going to get into where that is from!

Answer 4

Speed Of A Knot

Answer 5

This Site Might Help You.

RE:
in boat speed where did the term Knot come from and why is it different MPH?

Answer 6

The term "knot" came from old seafarers who used a rope with knots tied in it, spaced equal distances apart.
As the sailing vessel traveled the rope was drifted off the stern or back of the boat. Using an hourglass to calculate time, one hour, the rope was retrieved, and a deckhand would count the number of “knots”. Thus giving us the speed Knots per hour. 5knots= 5.8 mph

Answer 7

Quoting: {The speed of a vessel relative to the fluid itself, and not land, is referred to as 'boat speed' or, for aircraft, 'air speed' and is usually measured in knots. If the medium is flowing, this differs from the ground velocity by the velocity of the medium. Velocity made good refers to ground velocity and may also be expressed in knots in navigation.}

Answer 8

Bearsie is closest. A knot is derived from a measured length of line with knots spaced equally along it. As the old sailing ships went through the water, this line was todded over the stern with a "plug" on the end of it that would act as a sea anchor. The sailor holding the line would let it slip through his fingers, counting the number of KNOTS that passed through his hands over a specific measurement of time.

Answer 9

Derrick has it first. Just multiply the knots by 1.15 and get the answer in mph. It is 1.15 because a nautical mile is longer then a statute(land) based mile 6060 compared to 5280.

Answer 10

It is short for nautical mile per hour. A nautical mile is slightly longer than a land mile.