Count the molecules and multiply by the molecular weight.

I know it's a joke, but that doesn't help. So-called molecular weight is not an actual weights but a ratio - ratio of mass of the molecule to 1/12 of the mass of a carbon atom.

And you need to know Avogadro's number as well.

Cheers..........Codey

You know that, & I know that - and maybe it will occur to Mr Morris before he's finished counting .

Volume is cross sectional area (pi x r²) times length, multiply this by the density (which any search engine will find)
Del

While we're at it, why not tell him the density? 8000 kg/m3 near enough for practical calcs. And if he isn't working in metric - well, he ought to be!

BTW, he didn't say bar was circular cross-section.

Cheers.........Codey

Was it asked for a ROUND bar?

if he's working in Inches, multiply by .266 to get pounds..

Dear Sir

Wt of Steel Bar= Area of the bar Χ Density of the Bar

= (π d² )/4 Χ 7850 Ton/m²

Calculate the volume in inches³. Make certain you are on earth. Determine the type of steel. Multiply the volume by the appropriate density in lbs per cubic inch.

Much of this sort of thing can be looked up in Kempe's Engineers' Yearbook, any edition.

Steel weighs approx 490 pounds per cubic foot, with slight variations for alloy/grade.

I'm using 7850 Kg/m3 for Carbon Steel and 7950 Kg/m3 for Stainless Steel as an assumption.