Originally posted by: sao123
Originally posted by: KK
Originally posted by: PurdueRy
Originally posted by: KK
Originally posted by: gsellis
Negligible. There is some parasitic force on the plane because of resistance to spin in the wheels from inertia and friction. Otherwise, all force on the wheels translates to acceleration of the wheels. Remember physics where velocity is the speed along a specific vector for a period of time. Changing the vector is acceleration. F = ma. Assume mass =1 and F=a. A=dV/dt. So, just the wheels spin because that is how they work. Since they freewheel (except for that parasitic stuff), nothing on the plane allows energy the wheels store effect the plane. If you applied the brakes, then you translate the energy into heat and force on the plane, but only then.Originally posted by: KK
So are you saying the belt has zero effect on the plane? Zero, Nada, Nil?
But there is some, negligible at best, but that's all that's needed for people interpret this question in a different light. Mythbusters did it their way, but with most of the naysayers, they would say mythbusters didn't do it right per the question they heard or how they interpreted it. I don't think this is so much of a problem with physics but more to do with comprehension.
If you wanted to keep the plane stationary the treadmill would have to run at speed MUCH faster than the forward velocity of the plane. This would contradict the myth as stated. There is NO statement in the myth that says the plane will stay stationary. The only people that say this are the people that think a plane is a car with wings.
I don't believe many people actually believe that last sentence, atleast I hope not. I'd like to see the actual original myth if possible, not the version that mythbusters got handed, but the original.
The earliest dated reference to the problem is in the November 27, 2005 issue of
The Pilot's Lounge #94: It's The Medium, Manfred
http://www.avweb.com/news/pilotlounge/191034-1.html
"On a day with absolutely calm wind, a plane is standing on a runway that can move (some sort of band conveyor). The plane moves in one direction, while the conveyor moves in the opposite direction. The conveyor has a control system that tracks the plane speed and tunes the speed of the conveyor to be exactly the same (but in the opposite direction). Can the airplane ever take off?"
An earlier reference:
Text