The equation m=19.32v can be used to find the mass m in grams of a pure gold coin with volume v in cubic centimeter

Yes it can !

The reason is because every cubic centimeter of pure gold
has 19.32 grams of mass.

Another way to say that is:

       "The density of pure gold is 19.32 grams/cm³ ."

If milk had the same density as pure gold, then a gallon jug
of milk would weigh about  165 pounds !  You'd need your
dad to help take it out of the fridge when you wanted to drink
some, and when you put it back, you'd have to be verrry careful
which shelf you put it on.

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