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by timthorn
5259 days ago
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I'm not convinced by 2 of the answers to their 5 question pop quiz: > Q: How much does the Earth weigh? A: 1,000 trillion metric tonnes But isn't asking the weight (and not mass) of a planet fairly meaningless? > Q: How do aeroplanes stay up? A: The upward lift of a plane is created by its curved wings Isn't the dominant component due to downward deflection of oncoming air? |
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