by Guest » Fri Aug 05, 2005 6:40 pm
It is only "the same" for water or things that have the same density as water. A liter of lead is much heavier than a kilogram, a liter of feathers, lighter.
In cooking, most liquids are close enough to the density of water to get by, but flour, sugar, etc are not. You have to find the bulk density.
For petroleum products, gasoline is considerably lighter than water, heavy fuel oil is slightly lighter than water. Salt water is heavier than fresh water. There are no good approximations; you have to find data on the density.
If it floats, it's lighter than water. If it sinks, heavier.