Of course 一斤棉花重

來源: pinfan 於 2010-01-07 22:51:22 [] [舊帖] [給我悄悄話] 閱讀數 : (586 bytes)
回答: 一斤棉花重 由 pinfan 於 2010-01-04 19:38:47

1. All objects in the atmosphere are affected by air buoyancy. The larger it is, the more buoyancy on it.

2. The weight of an object (we can see on a scale) = the weight in vacuum (mass, quantity) minus air buoyancy.

3. The volume of cotton with the same weight is much larger than iron. There is much larger air buoyancy on it.

4. When we weigh 500 gram of cotton in the air, it contains more mass than 500 gram iron.

So, 一斤棉花重.

BTW, I believe such question can be found in Chinese book "100,000 Why". Most teenagers might know it.

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