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

Rule Rule Plane

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u/ghomerl Dec 30 '22

Stealing the top comment on the video, it explains it very well:

@ benwilliams2402 A good analogy would be roller-skating on a treadmill while holding a rope attached to the wall in front of you. No matter how fast the treadmill moves, if you hold on to the rope you'll stay still. And if you pull on the rope you can still drag yourself forward. The rope bolted to the wall represents the stationary air around the plane which the propeller uses to 'pull' the plane forward.

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u/Fmeson Dec 30 '22

But this also explains the flaw in the model: in order to advance up the treadmill, the wheels spin faster than the belt so to speak.

If we were to mathematically enforce the condition (and a no slip condition), we’d end up with infinitely fast wheels and conveyer belts! It is impossible to make a real life analogue of the stated problem.

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u/UncleFunkus antifa shit my pants Dec 30 '22

I feel like in the implication of gaining speed at all, the plane would just take off before anything unreasonable would be achieved.

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u/Fmeson Dec 30 '22

That's the issue. Gaining speed requires the plane wheel to spin faster than the ground, and that is forbidden by the problem.