The dry weight of a medium density concrete block (215 x 450 x 100mm thick) is approximately 7.5Kg ---There are many different sizes, shapes and mixes used to make concrete block.Additionally the...
The SI unit of volume is the derived unit of cubic metres. A more convenient unit to use for most practical purposes is the Litre. There are 1000 litres in one cubic metre.
Because the rest of the world uses the metric system. If you leave the U.S., science is still science. If we used our system, it would be hard to convert our discoveries.