Meters
The standard unit to measure mass is kilograms.
feet
Meters
feet
millimeter
The standard unit to measure mass is kilograms.
feet
The most appropriate metric unit to measure the mass of a concrete block is kilograms (kg).
Meters
millimeter
feet
kilograms
Centimeter
Kilograms are the most appropriate.
Feet
Litres.
The appropriate measure would depend on whether you wanted to measure its circumference, area, volume, temperature or some other attribute. For this reason, it is not possible to name an appropriate unit.