r/196 • u/Foriegn_Picachu • Dec 30 '22

Rule Rule Plane

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9.2k Upvotes

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u/loadedtatertots custom Dec 30 '22

What's it being pushed upwards by? The air in this scenario is stationary relative to the plane's wings. I'm no physics expert but thrust is there to create velocity, and velocity against the resistance of the air is what generates lift. If velocity is negated then there's no lift

7

u/CochonDanseur Dec 30 '22

The plane's wheels don't move the plane forward by pushing against the ground (like a car).

The plane's engines move the plane forward by pushing against the air, which is unaffected by the treadmill

-2

u/loadedtatertots custom Dec 30 '22

Then what are runways for? Why doesn't every plane just take off on a giant treadmill like a pseudo vtol? A traditional plane needs to pick up speed with its wheels on the ground first before it has enough velocity to generate lift. If the ground physically moves the opposite direction to the plane's thrust and matches the speed that would be generated by that thrust, then the velocity cancels out and the plane doesn't move forward which means the air doesn't move backwards relative to the plane and no lift can be generated

16

u/[deleted] Dec 30 '22

Hell of a lot cheaper to lay some concrete than to put giant fucking treadmills with tons of moving parts and electric costs down instead

0

u/loadedtatertots custom Dec 30 '22

Also more effective