Question

A piece of wood is $3\text{m}$ long, $2\text{m}$ wide, and has a thickness of $1\text{m}$. Find the density, if its mass is $2\text{kg}$.

• A. $0.33{\text{kg m}}^{-3}$
• B. $0.33{\text{kg m}}^{-3}$
• C. $0.33{\text{kg m}}^{-3}$
• D. $3{\text{kg cm}}^{-3}$

Answer 1

The correct option is A $0.33{\text{kg m}}^{-3}$

Volume of the wood (cuboid) is given by the product of its dimensions.
$V=1\times 2\times 3\text{m}$
$V=6{\text{m}}^3$

Density of wood is given by:
$\rho =\frac{m}{V}$
where:
$m:\text{Mass of wood}$

$\rho =\frac{2\text{kg}}{6{\text{m}}^3}$
$\rho =0.33{\text{kg m}}^{-3}$