Note these facts ;
Density of Steel = 7850kg/m³
Density = mass / volume
Volume of steel= πr²L, where r is the cross sectional radius of the steel and L is the length of the steel rod
Reinforcing steel for concrete is sold in lengths of 12m.
1 tonne = 1000kg
1m = 1000mm
Question: How many 12mm reinforcing steel will be sold to you per tonne.
Cross sectional radius is 12mm /2 = 6mm
Length of steel is 12m, therefore
Volume of steel is πr²L, that is;
3.142×(6/1000)² ×12= 0.001357344m³
Since, Density = mass / volume, it also means that;
Mass = density × volume
That is; 7850kg/m³ ×0.001357344m³
Since 1 tonne is 1000kg it implies that 1000kg/ 10.66kg= 93.81 but you will be supplied 93 pieces.