The ground has nothing to do with it. The ground could be moving forward at a zillion miles an hour or backwards at a zillion miles an hour; it wouldn't make a difference* so long as you assume the connection between the plane and the ground to be frictionless (read: perfect bearings). The plane cares only about the speed of the air; that'* why pilots fly on indicated air speed (which, as an aside, is also affected by pressure) instead of ground speed.


*There are a couple of subtle issues that make this not quite true, but unless you can name what they are, you don't need to worry about them

If the treadmill is set up like in the drawing that Pdad posted then yeah, the plane could take off because its thrust would overcome the friction from the wheels. It is impossible though, for the plane to "hover" in place. Without a sufficient airspeed, the airfoil will not create the pressure difference over the top and bottom of the wings needed to produce lift.

Planes use a small tube mounted on the wing or fuselage to measure airspeed, there are no wheel speed sensors.

Willwren, wouldn't the trucks mass be the same, but the weight would be less. The birds are no longer producing a downward force on the truck so their weight wouldn't matter.

Bingo. But I did state "Box Truck". The downward force of the wings is opposed to their weight (and roughly equal).

Yay, so I was right. Wow, I can't believe it.

What i cant figure out is why ppl are still having trouble figuring out this plane thing,..
I will take off there will be no differance in how long it ould take to take off because the speed requierd for take off would not affect the wheel bearings (even if whells speed was doubled be the treadmill) so in conclustion...There is now F***ing differance period!

Now start figuring out Wills mind bender...atleast that one is a little bit hard...im thinking that the truck would weigh less, i think there has to be a physical conetion betweem the birds and the cages for there weight to be transfured to the truck.
however i can see it CC'* way in the if the truck was 100% sealed then the weight would be the same because the birds are still displacing the same amount of air and if no air can get in or out the nothing in the truck would have changed thuse weight stays the same.

so now im back to squar one on this and dont know which it would be :? (but im leaning more towards my first thought


EDIT:...man i take too long to wight this stuff...three post in the time it took me to write.... and i was wrong!!

Peter, my dear Sir. Do me a favor.





Go shotgun 56 beers and come back to the problem with a fresh mind.

:?:

Why are we talking about a big freaking treadmill? Just put a big fan in front of the plane blowing towards it, and the plane will take off without moving forward.

On the treadmill part...we should all know...the engines move air..not it'* wheels..it flies.

On the truck..sounds like a trick question. The truck weighs 5000...the load it with birds..hit a bump..how much does the truck weigh.... No one asked how much does it weigh with cargo included.