Mythbusters tonight

[westexasrepublic]

well heres an easy physics answer, dont hurt your brain thinking too hard...It would be similar to have a plane in "neutral" at full throttle. that is assuming the treadmill is going fast enough to keep from any foward movement in the wheels to transfer into foward movement of the actual plane, (potential and kenetic energy). SIMPLE

[Mountaineer]

Your still going to have to travel through air. Basically the treadmill is just a slingshot to build up the neccessary speed, just like a catapult on an aircraft carrier. You arn't magically going to be flying when the power to the treadmill is shut off.

[fleaofsc]

Oh.... I didn't realize that the treadmill would be shut off. That makes this a little more debatable.

[Mountaineer]

it can be on or off. Regardless, the plane won't fly unless it travels any sort of distance.

[Mainerunr]

treadmill will spin the tires, big deal, planes dont propel with their tires so, the props or jet engine will push against the air like they always do, the treadmill will add a little resistance at the 'freely spinning*' wheels and the plane will take off.

* - freely spinning as in they are not driven but yes, there will be a little friction, no biggie.

oh, and of course there's no wind when you run on a treadmill, your propulsion system is the very thing in contact with the treadmill, not so with an airplane. the plane pushes against air, not the ground.

do we really have to relive this again?

[fleaofsc]

So what is even keeping the plane on the treadmill... I would say that it would just roll forward past the treadmill as if it wern't there. The treadmill would just make it spin its tires faster for a second.

[Avplayer]

an airplane needs to have airflow flowing over its wings to generate lift....the engines are there to "push" the airplane fwd thru the air....hasn't anyone stuck there hand out the window of a moving car? thats aerodynamics at work

[Mainerunr]

Originally Posted by Avplayer

an airplane needs to have airflow flowing over its wings to generate lift....the engines are there to "push" the airplane fwd thru the air....hasn't anyone stuck there hand out the window of a moving car? thats aerodynamics at work

exactly, the tredmill is irrelevant because it acts on the wheels (which spin relatively freely) while the plane's engines act upon the air thus allowing the plane to move forward regardless of what the treadmill is doing. since the plane is moving forward, it can generate lift and get off the ground.

what do you guys think the treadmill is doing to the plane to keep it from moving forward? the brakes on the wheels would be off so they can spin however fast the treadmill moves and it doesnt matter since that's not the method of propulsion for the plane.

why is there even a question here? the plane will move forward.

[CT_Nismo]

This problem would not be worthy of a "Physics for non-physics majors" type of class. No thinking involved with this one. I wonder how the demonstration will be staged?

[YOURADHERE]

I think it is one of those questions that seems simple but can be over-analyzed.