>>>>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.
>>>>
>>>>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.?
>>>
>>>Can we consider Eiffel Tower as cylinder?
>>
>>Only if it looks to you as cylinder.
>
>I don't think it's conus (?) either. When what?

Assume it's a pyramid - but its shape is irrelevant. The problem would have the same solution even if it was a cylinder, cone, ball or human figure.