In the classic wording of the old physics question -
"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. This 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 plane take off?"

Watch Adam and Jamie tackle this in famous MythBusters Style!

Talk About It Here!

MythMod

I'm glad this is finally going to be settled.



*Bwuahahahahahahha*

Yeah right.

to put this as simple as possible. what gives a plane thrust? Its wheels, or its propeller... The propeller moves the air around it, this has no berring on what the wheels are doing. The plane will take off

the only way to make a plane "in effect" hover on take off is to put it in a wind tunnel that matches wind speed with the plane giving it enough lift to relativly hover...

They're doing it all wrong!

It should be a 747 on a human sized treadmill going at the speed of light.

I've been waiting for the "they got it wrong" reasons for months.

Later!

ps. Is there a "will fly" party anywhere?

this is such a stupid myth for anyone that knows physics. One question what makes an airplane life? Answer the wings need lift, and the lift comes from the air moving over the wings and they lift with the plane. And on a conveuor belt the air isn't going to move any faster over the wings since the plane will stay statinary.

quote:

this is such a stupid myth for anyone that knows physics. One question what makes an airplane life? Answer the wings need lift, and the lift comes from the air moving over the wings and they lift with the plane. And on a conveuor belt the air isn't going to move any faster over the wings since the plane will stay statinary.

And anyone who *understands* physics has told you over and over again that the plane will not stay stationary.

quote:

Originally posted by danielson782:
this is such a stupid myth for anyone that knows physics. One question what makes an airplane life? Answer the wings need lift, and the lift comes from the air moving over the wings and they lift with the plane. And on a conveuor belt the air isn't going to move any faster over the wings since the plane will stay statinary.

HA HA HA!!! Thats great! Wow...I don't even know what to say to that.

quote:

this is such a stupid myth for anyone that knows physics. One question what makes an airplane life? Answer the wings need lift, and the lift comes from the air moving over the wings and they lift with the plane. And on a conveuor belt the air isn't going to move any faster over the wings since the plane will stay statinary.

You obviously haven't been paying attention to the show.

quote:

this is such a stupid myth for anyone that knows physics. One question what makes an airplane life? Answer the wings need lift, and the lift comes from the air moving over the wings and they lift with the plane. And on a conveuor belt the air isn't going to move any faster over the wings since the plane will stay statinary.

Erm... you are aware that there's a television show, on television, right now, I mean right, right now, I mean at this exact instant, that explains exactly why you're wrong, aren't you?

Quick everybody... what channel is it on? I can't remember...

I only have one problem with this myth. I am wondering where is there a conveyor belt/treadmill near a runway where a plane can take off. It is a good myth, but I have never seen a conveyor belt or treadmill big enough that a plane, any size, can take off of it. Sure, a plane can take off of a conveyor belt or treadmill because the wings give the plane lift so it can take off, but I don't see why someone would put or design a treadmill or conveyor big enough so a plane can take off.

Like said before a plane needs lift to "take off". This lift is provided by air passing over the wings. I a plane is on a conveyor that accelerates at the same rate at the plane, keeping the plane stationary, the plane will not have the lift to leave the groung. The same scenerio can be done by tying a rope to the tail of the plane. the plane will remain stationary because of the rope holding it back, and it will not take off because it will not have any air passing over the wings except for the air from the propeller. Unless the air from the propeller is enough to provide lift, the plane will stay grounded...

quote:

Erm... you are aware that there's a television show, on television, right now, I mean right, right now, I mean at this exact instant, that explains exactly why you're wrong, aren't you?

Quick everybody... what channel is it on? I can't remember...

Don't be a meanie, eightbit Up here in Canada, Discovery is showing Mike Rowe... we won't get to watch the POAT episode for a while.

quote:

Originally posted by soc21lax40:
Like said before a plane needs lift to "take off". This lift is provided by air passing over the wings. I a plane is on a conveyor that accelerates at the same rate at the plane, keeping the plane stationary, the plane will not have the lift to leave the groung. The same scenerio can be done by tying a rope to the tail of the plane. the plane will remain stationary because of the rope holding it back, and it will not take off because it will not have any air passing over the wings except for the air from the propeller. Unless the air from the propeller is enough to provide lift, the plane will stay grounded...

Are you watching the show?

quote:

Like said before a plane needs lift to "take off". This lift is provided by air passing over the wings. I a plane is on a conveyor that accelerates at the same rate at the plane, keeping the plane stationary, the plane will not have the lift to leave the groung. The same scenerio can be done by tying a rope to the tail of the plane. the plane will remain stationary because of the rope holding it back, and it will not take off because it will not have any air passing over the wings except for the air from the propeller. Unless the air from the propeller is enough to provide lift, the plane will stay grounded...

You have got to be kidding me. Watch the show...you're wrong. This time, we don't even have to explain; we'll just direct the no-flys to the episode guide.

With what echo4charlie said as well as Adam & Jamie's demo with the electric car explaining why they thought the model airplane was able to take off, why was this even an issue of centention to start with?

NOW LET THE WHINING BEGIN!!!

What will the excuses from the "no-fly" segment be?
Will they argue it wasn't a REAL conveyor belt, even though it served the exact same purpose?
Will they argue the speed wasn't high enough, even though it was higher than the take-off speed?
Will they argue that a larger plane will behave differently, even though they use the same physics?
Or... will they agree they were wrong, and say so?

I'll say it, I originally thought the plane would not take off. I sat through a couple explanations, until I understood the physics, then decided they were probably right, and it would. But I always had a tiny amount of doubt.

Glad to see it prven Busted. Great job guys!
wolfy

HA HA HA HA HA!!!!!! IT FLEW!!!!!!

I have to say, it wasn't what my wife and I expected. It's 100% understandable that if the plane is moving, it's going to take off - that's simple physics. What we were EXPECTING (take note for a revisit!) was that the plane and treadmill would match speeds - i.e. that the plane would remain stationary with respect to the ground. That's what the early explanations of the myth said - the plane moves x MPH one way, the treadmill moves x MPH the other way, the result being that the plane doesn't move forward or backward with respect to the ground. In both the model and full-scale tests, the pilot overaccelerated - of course it took off.

Do it again and keep the plane still - that would be the REAL test. :-)

i think that they totally

quote:

half-assed

it because when they were explaining the myth they said it as if the plane isnt moving forward on the tredmill but when they actually the did the myth the plane ACTUALLY WAS MOVING FORWARD and was able to get some thrust and achieve flight so i think they need to re-do this one