How fast is 1 knot?

[Paul Foster]

My son asked me today how fast is 1 knot (in MPH) and I had no idea how fast
it was!

Can you help?

TIA

Paul

[Pete Styles]

1 knot is one nautical mile per hour.
If you are wondering why we bother with the nautical mile, its because its 1
minute of latitude (ie 1/60 of a degree) and therefore very useful to, for
example, sailors, because it can be directly measured from the latitude scale on
a chart. Thus it has a direct relationship to the size of the earth. The usual
rule of thumb is that it's one and a seventh of a statute mile per hour.
HTH,
P.

Paul Foster wrote:

> My son asked me today how fast is 1 knot (in MPH) and I had no idea how fast
> it was!
>
> Can you help?
>
> TIA
>
> Paul

[Pete Styles]

>
> You are quite right Peter, a nautical mile is approx 800 feet longer than a
> statute mile, my apologies.
>
> My Garmin, when used in the car, disagrees with my speedo as the Garmin is
> set to nautical miles, but the new tyres I have just fitted mean that the
> rev. counter no longer reads as fast for a given speed than before the tyres
> were fitted.
>
> If I therefore set my Garmin to read statute miles, or even kilometers, am I
> likely to win more races if I buy new sails for the yacht?
>
> Dennis

<g>
Sadly, talent and money seem to be the only recipe for success, and I can't lay
claim to enough of either!

[Alan Frame]

Peter Verdon <news@verdonet.organisation.unitedkingdom> wrote:

> (That is, 1 knot is 1.15mph; 1mph is 0.87kt.)

Things can get 'interesting' when one forgets to switch a GPS from knots
to statute when moving it from a boat to a car....

rgds, Alan

[Jeff Richards]

Sigh. Please replace every reference to longitude in the above post with
latitude, and remove the last comment.
--

"Jeff Richards" <JRichards@********.au> wrote in message
news:VkpEc.70914$sj4.27790@news-server.bigpond.net.au...
> According to Peter Heaton 6080 was decided because it is the length of a
> minute of longitude at latitude 48 degrees. He suggests that this is an
> 'average', but I rather think it was convenient for British sailors.
>
> My calculation for latitude 48 gives 1853.17 metres or 6079.16 feet, which
> I guess is within the error of the calculation. It's
>
> 111132.92 + (-559.82 * Cos(2 * L)) + (1.175 * Cos(4 * L)) + (-0.0023 *
> Cos(6 * L))
>
> where L is the latitude. Working backwards, this means that the new unit
> of 1852m is exactly one minute of longitude at latitude 44.4.
>
> Note that your 60.3 NM is at 90 degrees latitude, where a minute of
> longitude has become a little irrelevant!
> --