3 ms·
I think you've changed definitions on the fly. Both the higher pressure on the bottom and the lower pressure on the top contribute to the lift. If you use a su
by Gravityloss 11y ago
I think you've changed definitions on the fly. Both the higher pressure on the bottom and the lower pressure on the top contribute to the lift.
If you use a suction cup to lift a piece of horizontal glass, well, I think most reasonable people would say it contributes a force. Maybe you'd say no it doesn't, you don't actually lift it, you just provide a lower pressure at the top allowing the bottom air pressure to push it up... Well duh, of course.
- Retric 11y agoI don't think science should care what 'reasonable people' believe, because reasonable people are often wrong. The whole point is to build accurate models of the world and perpetuating a myth is harmful in the long term. PS: Can you point to where you think I changed definitions? I may have been less than clear.
- Gravityloss 11y agoYour definition of lift is very different from the commonly accepted one. If an aircraft that weighs 1000 kg flies level, then the lift has to be 9800 newtons. That means the lift is the sum of the effect from both the bottom overpressure and the top underpressure. You can check it from any dictionary. https://en.wikipedia.org/wiki/Lift_%28force%29 https://en.wikipedia.org/wiki/Lift_%28force%29
- Retric 11y agoIn level flight every actual force vector above the wing is lowering the magnatude of lift. If you owe 2000$ and have 2200$ your net worth is positive 200$. But, people don't talk about debt as adding to your net worth even if it's part of the equation debt is reducing the result not increasing it. PS: I agree you don't need to model the 2.1 tons per square foot of force in most situations. But, just because you ignore something does not mean it goes away.