How much is a 16 mm diameter 796 meter long steel bar The density is 1.579kg/m

How much is a 16 mm diameter 796 meter long steel bar The density is 1.579kg/m

How much is a 16 mm diameter 796 meter long steel bar
Formula: w = f × L × ɡ × 1 / 1000
In the formula
W -- weight, unit: kg;
F -- sectional area, unit: mm & # 178;;
L -- length, m;
ɡ - specific gravity, unit: 7.85g/cm and#179
The density is 1.579kg/m, wrong?
In physics, the mass per unit volume of a substance is called the density of the substance. The symbol ρ (read as R ō U). The international main unit is kilogram / meter and#179; and the common units are
In the international system of units, the main unit of mass is kilogram, and the main unit of volume is cubic meter. Therefore, the mass of one cubic meter of material is taken as the density of material. For non-uniform material, it is called "average density"
Now no matter right or wrong, we have to follow your idea, density is 1.579kg/m ᦉ 179; = 1.579kg/m ᦉ 179; △ 1000 = 0.001579g/cm ᦉ 179; (normal specific gravity is 7.85g / cm ᦉ 179;); diameter of steel bar d = 16mm; length (L) = 796M
Substituting formula:
　　①W＝π×D²/4×L×ɡ×1/1000＝3.1416÷4×16²×1×0.001579×1/1000×796＝0.7854×256×1×0.001579×0.001×796＝0.00031747752（㎏/m）×796（m）＝0.25 （㎏）.
　　②W＝πr²×L×ɡ÷1/1000×796＝3.1416×8²×1×0.001579×0.001×796＝0.00031747752×796＝0.25（㎏）.
If: ɡ - specific gravity, unit: 7.85g / cm and#179;, the weight of 16mm long 796M steel bar is heavy
　　W＝π×D²/4×L×ɡ×1/1000＝3.1416÷4×16²×1×7.85×1/1000×796＝0.7854×256×1×7.85×0.001×796＝（㎏/m）×796（m）＝1256.35851264（㎏）＝1256（㎏）.
A: according to the conventional theory, a steel bar with a diameter of 16mm and a length of 796M has 1256kg. However, if you set the density (specific gravity) as 1.579kg/m (1.579kg / M), a steel bar with a diameter of 16mm and a length of 796M has only 0.25kg