The picture shows a model terracotta warrior. The model has height of 15 cm and weighs 20 grammes.
A similar terracotta warrior has a height of 1.8 metres. Find the weight of the larger terracotta warrior.
Give your answer in kilogramme, correct to 1 decimal place.

1. Convert the larger height to the same unit and find the linear scale factor.

$1.8\text{ m}=180\text{ cm}$

Linear scale factor from model to larger warrior:
$\frac{180}{15}=12$

2. Use the cube of the linear scale factor to find the weight in grammes.

For similar solids, weights are proportional to volumes.

Volume/weight scale factor:
$12^3=1728$

Weight of larger warrior:
$20\times 1728=34560\text{ g}$

3. Convert grammes to kilogrammes and round to 1 decimal place.

$34560\text{ g}=34.56\text{ kg}$

Correct to 1 decimal place:
$34.56\text{ kg}\approx 34.6\text{ kg}$