Density = Mass/Volume so Volume = Mass/Density
I would guess 250 grams.
"16 mm" probably refers to the diameter. The mass of a steel bar depends not only on its diameter, but also on its length.
You need more information than mass and diameter to calculate density
You cannot, there is no single-rule, formulaic relationship between mass and physical measurements like length or diameter.
There is no intrinsic relationship between mass and length or diameter. A line segment or diameter has no mass. So you can double its length and the mass remains unchanged.
by condromising the the mass and diving the mass by the diameter of volume.
Density or weight is calculated by mass/volume
You cannot. The mass depends on the material of the shaft and that has not been specified.
Kilogram is a unit of mass, not of length.Kilogram is a unit of mass, not of length.Kilogram is a unit of mass, not of length.Kilogram is a unit of mass, not of length.
Given mass divided by moles of molecules.
Mass = force/acceleration
given mass / molar mass is one of the ways.
Acceleration = (force) divided by (mass)
Divide the mass by the volume: density = mass ÷ volume