Question:
A solid rectangular piece of iron measures 1.05 m × 70 cm × 1.5 cm. Find the weight of this piece in kilograms if 1 cm3 of iron weighs 8 grams.
Solution:
$1 m=100 \mathrm{~cm}$
$\therefore$ Dimensions of the iron piece $=105 \mathrm{~cm} \times 70 \mathrm{~cm} \times 1.5 \mathrm{~cm}$ Total volume of the piece of iron $=(105 \times 70 \times 1.5)=11025 \mathrm{~cm}^{3}$
$1 \mathrm{~cm}^{3}$ measures $8 \mathrm{gms}$.
$\therefore$ Weight of the piece $=11025 \times 8=88200 \mathrm{~g}=\frac{88200}{1000}=88.2 \mathrm{~kg}$ (because $1 \mathrm{~kg}=1000 \mathrm{~g}$ )