The Metre is dead easy to remember cos its equal to 1,650,793.73 wavelengths of the orange-red emission line in the electromagnetic spectrum of the krypton-86 atom in a vacuum
Dead easy, ahem.
Dead easy, ahem.
conversions
- Thread starter entropydog
- Start date
-
Hey Guest, Early bird pricing on the Summer Moot (29th July - 10th August) available until April 6th, we'd love you to come. PLEASE CLICK HERE to early bird price and get more information.
And Celsius, being a centigrade system, is by definition a "decimal" (divisible by ten) system.
Everyone thinks we use decimal measure, but that's not true. What we use is SI units. There are seven basic units (Kg, metre, second, Ampere, Kelvin, Candela and Mole) from which all other units are derived. (For example the unit of speed is metres per second) SI just happen to be based on the convenience of a base ten system.
Everyone thinks we use decimal measure, but that's not true. What we use is SI units. There are seven basic units (Kg, metre, second, Ampere, Kelvin, Candela and Mole) from which all other units are derived. (For example the unit of speed is metres per second) SI just happen to be based on the convenience of a base ten system.
Actually the basic unit there is the gram, not the Kg. The Kg (a 1000 multiple of the basic gram) is more useful for larger items simply because the basic gram is just too small and the numbers would be too large. Just as when measuring still larger items we switch to the Mg (Megagram, or 1 million grams) more commonly known as a metric ton.
None-the-less they are all derived from the basic gram.
Last edited:
Pedantically it isn't, it's just named that way. The Kilogram is defined as the mass of a lump of stuff held somewhere somewhere in France (I may have paraphrased
). The Gram is defined as 1/1000th of a Kilogram so is in fact derived from the gram.They probably mean 1016Kg, 1000Kg is a tonne
Last edited:
So navigation
Degrees or Mils ???
and explain to me why its actually technically more accurate to use degrees when using a basic hand held compass
ATB
Duncan
Degrees or Mils ???
and explain to me why its actually technically more accurate to use degrees when using a basic hand held compass
ATB
Duncan
No. They mean 2,240 lbs or 20cwt (1cwt=112lb). Twenty hundredweight is a ton.
The metric tonne is distinguished from the Imperial one by the spelling.
or 14593 slugs
No, a slug is a mass of around 14.6kg so 1000/14.6 is about 68.5 slugs.
http://en.wikipedia.org/wiki/Slug_(mass)
So navigation
Degrees or Mils ???
and explain to me why its actually technically more accurate to use degrees when using a basic hand held compass
It makes no difference to accuracy which system you use. Trivial rounding errors aside, the accuracy depends on the ability accurately to read the displayed measurement, not on the units of the display.
No, the fundamental unit in the MKS (SI) system is the kilogram.
http://scienceworld.wolfram.com/physics/SI.html
The gram was used in the old CGS system, no longer considered useful. The unit of force in the CGS system is the dyne, in the MKS system it is the Newton.
http://en.wikipedia.org/wiki/Dyne
http://en.wikipedia.org/wiki/Newton_(unit)
yes its a theoretical question to counter the usual " there's 6400 mills in a circle and only 360 degrees .......... mils is obviously more accurate " brain wash you get out of some military biased views
the answer should lay in the "basic hand held compass" I specified in the question and your "the accuracy depends on the ability accurately to read the displayed measurement" when applied to that item
ATB
Duncan
Not sure about the official defintions but over here, yes, when people say a "ton" it does mean 1000Kg (2200 pounds) if they're working in metric (usually they'll phrase it either as a "metric ton" or a "long ton") A standard Imperial ton over here is still 2000 pounds while a "short ton" (used to weigh precious metals) is only 1600 pounds.
The different spelling (ton vs tonne) over here is usually just attributed to cultural differences (American vs European) rather than used to differentiate between measuring systems.
Last edited:
I studied Art and Education not Science, but I thought the metric system a by-product of the French Revolution and was based upon length and a subdivision of the earth's circumference: the basic unit being a metre. A 1000 cubic centimetres was the volume of a litre, and the weight of a litre of water was a kilogramme and so on. I know from carrying enough of it that a litre of water weighs a kilo.
In case anyone is listening, mine's still a pint!
In case anyone is listening, mine's still a pint!
There's method in all this:
The force required to accelerate one slug at 1 ft/s/s is one pound(f). Imperial system, sometimes called fps, and unsatisfactory because it has two units called the pound and they're different.
The force required to accelerate one gram at 1 cm/s/s is one dyne. Centimetre/gram/second system, or CGS, non-standardized and so unsatisfactory when it comes to electrical measurements.
The force required to accelerate one kilogram at 1 m/s/s is one Newton. Metre/kilogram/second system, or MKS. Finally, they got this one right.
Anyway, if you can get a grip on that you're well on the way to becoming a rocket scientist.
http://mysite.du.edu/~jcalvert/phys/cgsfps.htm
There's method in all this:
The force required to accelerate one slug at 1 ft/s/s is one pound(f). Imperial system, sometimes called fps, and unsatisfactory because it has two units called the pound and they're different.
The force required to accelerate one gram at 1 cm/s/s is one dyne. Centimetre/gram/second system, or CGS, non-standardized and so unsatisfactory when it comes to electrical measurements.
The force required to accelerate one kilogram at 1 m/s/s is one Newton. Metre/kilogram/second system, or MKS. Finally, they got this one right.
Anyway, if you can get a grip on that you're well on the way to becoming a rocket scientist.
http://mysite.du.edu/~jcalvert/phys/cgsfps.htm
Oddly, my first 2 years at university (1974-1976) were spent studying for a Bachelor's degree in engineering (I began as a civil engineering major but later leaned towards aeronautical engineering) My final Bachelor's degree was/is in Proffessional Aeronautics with a minor in Aviation Safety (finally awarded in 1994 after several interuptions for military service and only studying part time after duty hours)
Last edited:
You're mostly right about the origins. Except it's not a product of the French Revolution; it predates that. The French Revolution wasn't until 1789; The first US Congress debated using the metric system in 1787 (2 years earlier) but decided against it because GB was stil our main trading partner and it was still using Imperial. Although for some reason Wikki still shows it to have been introduced by france in 1799?
Last edited:
To convert to C from F I type "50F in C" into google and the answer appears.
In CZ a small beer is usually 300ml and a large 500ml, I guess 250ml just isn't enough for the CzechsI think you'll find on the Continent, beer is served in 250ml and 500ml volumes...
It's mass is almost exactly a kilogram but annoyingly not exactly. It's weight depends on many things but is not measured in Kilos
On earth it would weigh about 9.8 NewtonsSimilar threads
