• im_fine_sandy@nord.pub
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    11 days ago

    Why is 1 unit of volume 1000 units of weight?

    As in, 1 litre of water is 1 kilogram. 1 gram of water is 1 millilitre.

    Why couldn’t 1 gram be 1 litre?

    edit: a better way to phrase this question is as @sc00ter@lemmy.zip put it:

    The question wasnt about water specifically. Theyre trying to ask why does 1e3 mass = 1e0 volume and/or 1e0 mass = 1e-3 volume. Why doesnt 1e0 mass = 1e0 volume

    • polotype@lemmy.ml
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      11 days ago

      See, 1 liter isn’t 1kg , 1 litre of water weighs 1kg. There’s the difference, and as such there is no reasin for 1 litre of water to weigh 1 gram.

      • pneumaticFax@lemmy.world
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        11 days ago

        Kilogram is not the metric unit of weight, it’s mass. 1 liter of water has mass of 1kg. 1kg of water weighs 9.81 newtons - at least on earth. Newton is the metric unit of weight.

      • im_fine_sandy@nord.pub
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        11 days ago

        You don’t seem to have understood the question.

        1 kilogram is 1000 grams. Kilo isnused in place of the 1000.

        1 litre of water weighs 1000 grams. Why couldn’t it be 1 litre of water is 1 gram?

        • 666dollarfootlong@lemmy.world
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          11 days ago

          Because units less than a litre are so common. 2ml of syrup, 4dl of flour, 12cl of wine, 0.5l of beer, etc. But things you measure by mass rarely go below 1 gram (in day-to-day life at home). Candy bar is 50g, a packet of cheese is 200g, a chunk of meat is a kilogram. Besides, most people just call it “a kilo” so the common units in the spoken language are “a kilo” when talking about mass and “a litre” when talking about volume

    • SwingingTheLamp@piefed.zip
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      11 days ago

      The International System of Units (SI) uses the kilogram as its base unit of mass, so it is 1 thing in SI units = 1 liter, and SI is what most people think that they mean by “metric system” these days. Even though the SI isn’t entirely metric. (The Celsius scale isn’t, for example.) Also, liters are not SI units; the m3 is the SI unit of volume, and the liter was defined in terms of that.

      To put it another way, the base unit of mass is a kilo- of something, and it (not quite) equals a metric non-metric-system unit of volume of water. I dunno, the metric system seems all kinds of messed up to me!

      (/j)

    • ForeverComical@lemmy.ca
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      11 days ago

      It’s like the reason 0 is freezing water temp and 100 is boiling water.

      They used water as a standard when deciding what things ought to mean.

      • Sc00ter@lemmy.zip
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        11 days ago

        The question wasnt about water specifically. Theyre trying to ask why does 1e3 mass = 1e0 volume and/or 1e0 mass = 1e-3 volume. Why doesnt 1e0 mass = 1e0 volume

    • merc@sh.itjust.works
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      11 days ago

      The gram was originally defined as “the absolute weight of a volume of pure water equal to the cube of the hundredth part of a metre [1 cm3], and at the temperature of melting ice”.

      Why? Who knows. If they’d already decided on the meter, then the most logical definition of a litre is pretty awkward. You’d think it would be 1 cubic meter of water, because then the unit of volume is 1 unit of length cubed. Then one gram would be one litre of water, which is today 1000 kg, or one metric ton.

      But, then for everyday things people would be using microlitres and micrograms.

      Really, the metre should have been the replacement for the inch (i.e. the centimeter). Then you could have 1 litre being 1 cubic meter (what is today 1 mL) and then the unit of mass would be the mass of 1 L of water, which would be 1 gram. A person’s height would be in hm, and long travel distances would be in Mm.

    • MyButSmellsBat@feddit.org
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      11 days ago

      A litre is a unit of volume and just another way of saying 1 cm^3. It is a unit that is useful in daily life but it is not an SI unit. Since volume is only devrived from lenth you would need to either adjust lenth or weight for it to line up.

      Also your question is unclear (to me) would you like the gram or the litre to change so they line up “better”?

      • im_fine_sandy@nord.pub
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        11 days ago

        It doesn’t matter which one you change, the question is why are they not aligned. It seems like an obvious shortcoming.

        Like 1 megalitre of water could have weighed 1 megagram and so on.