>>Ok, I think this one is actually relatively easy - but I find it interesting nonetheless.
>>
>>Assume that the Eiffel Tower has a mass of 8000 tons, and a height of 300 m.
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>>What would be the mass of a model, made to scale - accurate in every detail, and made from the same material - having a height of 30 cm.?
>
>8 grams, assuming you mean metric tons.
In my understanding, that is the correct solution. Let me detail the solution, for the remaining participants.
Two similar objects have a volume that is proportional to the third power of any linear measure (height, circumference, etc.). This can easily be verified for some shapes for which you know the formula, such as a sphere, a cube, or a pyramid, but it is valid in general.
Therefore, 8000 tons / 1e9 = 8e6 kg. / 1e9 = 0.008 kg. = 8 grams.
(1e9, or 1000 millions, is the ratio - 1:1000 - to the third power)
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)