Dorset Boy
Über Member
- Location
- North Dorset or a mountain
Divide by 8, multiply by 5
or
divide by 5, multiply by 8
Depending on which way you are converting.
Not hard at all and close enough give 1 mile = 1,609 m
KM vs Miles
- Thread starter Aston
- Start date
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Divide by 8, multiply by 5
or
divide by 5, multiply by 8
Depending on which way you are converting.
Not hard at all and close enough give 1 mile = 1,609 m
slowmotion
Quite dreadful
- Location
- lost somewhere
Whatever is on the sign posts by the side of the road.
Dorset Boy
Über Member
- Location
- North Dorset or a mountain
And I googled it too!
its no more complicated than any measurement system is in mathematics, the trick is always knowing the conversions.
Im definitely not that old, Im post decimal, but was taught imperial in my formative years at my first school, all apart from temperatures thats always been Celsius.
it was only when we moved and I had to go to a new school that was more urban, that they started to mix metric and imperial up, which was quite confusing, like one of the sports lessons the teacher would often tell everyone to move a metre apart, and Id be waiting for everyone else to move because I didnt know how many feet that was, of course if anyone had bothered to say its about a yard, alot of school angst would have been solved.
so its miles on the bike, psi in the tyres, and the only reason I weigh myself in kgs now, is because it makes me feel slimmer
(because I cant convert them in my head to stones and pounds)
it was only when we moved and I had to go to a new school that was more urban, that they started to mix metric and imperial up, which was quite confusing, like one of the sports lessons the teacher would often tell everyone to move a metre apart, and Id be waiting for everyone else to move because I didnt know how many feet that was, of course if anyone had bothered to say its about a yard, alot of school angst would have been solved.
so its miles on the bike, psi in the tyres, and the only reason I weigh myself in kgs now, is because it makes me feel slimmer
(because I cant convert them in my head to stones and pounds)
Once a Wheeler
…always a wheeler
For terrestrial units I use metric measurements as most of the world works in this system. For nautical units I use nautical miles as each of these equals a degree of latitude and so is very easy to read off a chart.
Interestingly, the original calculation for the metre was also a terrestrial unit. In 1791 its length was defined as one ten-millionth of the distance from the equator to the north pole. I suspect it was chosen as a rationalization of the yard, pace or step which had been in use up to that time.
Another quirk of measurement is the unit used to express depths on nautical charts. Standard British Admiralty practice from the 1970s is to use metres for depth measurements. Even so, many older charts exist with depths expressed in fathoms, one fathom being six feet: so read the units when you go into port on a ship.
Aviation uses nautical miles for linear measurement, which is sensible as the distortions to distance imposed by various map projections make this the easiest unit to use. However, altitude seems to work best in metric with aircraft often flying at a height of around 10,000 metres, the Alps and Andes often topping out around 5,000 metres and the Himalayas at around 9,000 metres. For mountaineering, metres can also be useful as 100 metres of altitude roughly brings about a temperature change of 1° Celsius, which is a useful rule of thumb when choosing equipment.
Horses for courses as often mentioned above. One personal note to add: I habitually carry a steel rule with me, usually one with both metric and imperial units marked on it. Accurate measurement in any system saves so much trouble.
Interestingly, the original calculation for the metre was also a terrestrial unit. In 1791 its length was defined as one ten-millionth of the distance from the equator to the north pole. I suspect it was chosen as a rationalization of the yard, pace or step which had been in use up to that time.
Another quirk of measurement is the unit used to express depths on nautical charts. Standard British Admiralty practice from the 1970s is to use metres for depth measurements. Even so, many older charts exist with depths expressed in fathoms, one fathom being six feet: so read the units when you go into port on a ship.
Aviation uses nautical miles for linear measurement, which is sensible as the distortions to distance imposed by various map projections make this the easiest unit to use. However, altitude seems to work best in metric with aircraft often flying at a height of around 10,000 metres, the Alps and Andes often topping out around 5,000 metres and the Himalayas at around 9,000 metres. For mountaineering, metres can also be useful as 100 metres of altitude roughly brings about a temperature change of 1° Celsius, which is a useful rule of thumb when choosing equipment.
Horses for courses as often mentioned above. One personal note to add: I habitually carry a steel rule with me, usually one with both metric and imperial units marked on it. Accurate measurement in any system saves so much trouble.
Shut Up Legs
Down Under Member
Actually, aviation uses both imperial and metric, depending on how high the aircraft is and what the local atmospheric pressure is. I've worked on air traffic control software for some time now, and this is definitely one of its complicating factors.
Andy in Germany
Legendary Member
- Location
- Rottenburg am Neckar
Imperial:
12 inches = 1 foot
3 feet = 1 yard
22 yards = 1 chain
5,280 feet, or 1,760 yards, or 80 chains = 1 mile.
Metric:
10mm = 1cm
100cm = 1m,
1000m = 1km
Being "Mathematically challenged" I'm very glad I don't have to work in imperial measurements...
