Question

A bar measures 12 mm x 20 mm x 1 m. It has a specific gravity of 2.78. Determine its mass

Answer 1

Given:

$\rho=2.78=2780\:\rm kg/m^3$

$V=\rm 12\: mm\times20\: mm\times 1\: m=2.4*10^{-4}\: m^3$

The mass of a bar

$$m=\rho V=\rm 2780\: kg/m^3*2.4*10^{-4}\: m^3=0.667 \: kg$$