Mythbusters/airplane on a treadmill.

[JNickel101]

It will fly. The engine has more than enough power to overcome the friction between the wheels and ground as well as wheel bearings. They can't run a treadmill or anything fast enough to overcome the thrust of the engine and if they could it would fry the wheel bearings. I don't understand people think it wouldn't fly?

then where is the "myth"?

this is getting really stupid....

no kidding - if the plane can move forward fast enough, its gonna fly. i think everyone agrees on that.

 

[goodburbon]

when you run on a treadmill do you feel air on your face??

no

no air flow no lift.

assgas:

Please think a bit harder. when you are on a treadmill you are propelling yourself with your legs, not paddling through the air. Put roller skates on , a gigantic fan on your back and then step on a treadmill. (please post a video of this too)

You don't even need the fan to illustrate the point, you could just hold on to the handle and pull yourself forward. You'll notice that you can pull yourself forward wether the treadmill is on or not. The illustration is that the planes propulsion is independent from contact with the ground, like your hands pulling you forward as the ground moves backward. The wheels are just there to reduce friction as someone stated earlier.

 

[JNickel101]

All you guys that think the plane won't move... do you think this boat could travel against the current of a river?

Billy

make the amount of thrust = the speed of the river current

no, its not gonna move.

its the same concept as you running 8mph forward on a treadmill, while it spins 8mph backwards as well....

 

[JeepFreak21]

make the amount of thrust = the speed of the river current

no, its not gonna move.

its the same concept as you running 8mph forward on a treadmill, while it spins 8mph backwards as well....

At least you're consistent

How about a hovercraft?

Billy :laugh2:

 

[JNickel101]

The question states:

A plane is standing on a runway that can move (like a giant conveyorbelt). This conveyor has a control system that tracks the plane'sspeed and tunes the speed of the conveyor to be exactly the same (butin the opposite direction).Will the plane be able to take off? As you can read - the control in the experiment is that the conveyer is moving at the same speed as the airplane...

 

[goodburbon]

make the amount of thrust = the speed of the river current

YOU'RE NOT THINKING HARD ENOUGH!

The question does not limit the thrust, the question is "can the boat move upstream? " Do you understand why?

 

[JNickel101]

At least you're consistent

How about a hovercraft?

Billy :laugh2:

Whats your point? Educate me b/c I'm obviously missing something. You've apparently run on a treadmill a lot more than I have....

 

[JNickel101]

YOU'RE NOT THINKING HARD ENOUGH!

The question does not limit the thrust, the question is "can the boat move upstream? " Do you understand why?

Nope - never driven a hovercraft or fan boat. I run on treadmills though. And blow stuff up.

EDIT: THE MYTHBUSTERS QUESTON LIMITS THE THRUST, WHICH IS WHAT I'M SAYING

I'm thinking plenty hard enough - my point is if whatever is underneath you is moving in the opposite direction that you are trying to travel AND YOU'RE BOTH MOVING AT THE SAME SPEED, you're not gonna move forward....

jesus...what am I not saying clear enough?

 

[goodburbon]

go step on your goddamned treadmill with roller skates on.

 

[JNickel101]

good god...

yes, i see your point - if you increase your speed faster than that of the treadmill, yes, you'll move forward

my point is READ WHAT THEY ARE TRYING TO PROVE:

A plane is standing on a runway that can move (like a giant conveyorbelt). This conveyor has a control system that tracks the plane'sspeed and tunes the speed of the conveyor to be EXACTLY THE SAME (but in the opposite direction).Will the plane be able to take off?

 

[JNickel101]

Here's one for you....

How's a dyno that measures your power at the wheel work then? If we use your theory, it would fly right off the rollers and move forward....

 

[jeepboy381]

Nope - never driven a hovercraft or fan boat. I run on treadmills though. And blow stuff up.

EDIT: THE MYTHBUSTERS QUESTON LIMITS THE THRUST, WHICH IS WHAT I'M SAYING

I'm thinking plenty hard enough - my point is if whatever is underneath you is moving in the opposite direction that you are trying to travel AND YOU'RE BOTH MOVING AT THE SAME SPEED, you're not gonna move forward....

jesus...what am I not saying clear enough?

Okay, if the treadmill could keep up with the speed of the plane it wouldn't take off, no movement = no lift. But maybe people are trying to imply that the air pulled by the prop will lift the plane? The way I see it with the tarp moving backwards @ 80 mph it will only take a very very small extra amount of throttle to over come the backwards motion of the tarp because there will be no extra wind resistance. The only extra resistnace will be in the wheel bearings and tires. The thing is how are they going to get a tarp or treadmill moving at the same rate of speed it takes for their given plane to take off?

 

[jeepboy381]

What is the point of the test then, if the tread mill is moving at the same speed as the plane but in the opposite direction it won't fly. That is that. No movement = no lift!!

 

[JNickel101]

jeepboy381, thats what i've been saying for the last 30 minutes....

if you read the way their question is written, it states that the treadmill and the speed of the plane will be the same, just in opposite directions.

everyone seems to imply that i dont realize that if you move the speed of the boat/plane/runner/skate FASTER than the speed of the treadmill, that you won't move forward....well no shit Einstein....

 

[karstic]

I like pie.:lickout:

 

[98XJSport]

Again, you can't think of this like a wheeled vehicle.

Using a jet engine is easier let me try describing things that way.

A jet engine sucks air in and blows it out the back with lots of force, thrust.

The treadmill, assuming it's as powerful as the jet engines, travel in the opposite direction as fast as the jets wheels.

Therefore it's standing still... correct?

But the jet engine isn't fighting the treadmill. It's sucking in air and pushing forward. The free spinning tires won't have enough friction, or traction, against the treadmill to stop this from happening.

And as long as the jet engine pulls and pushes air, it's going to go forward. Which will generate lift...

 

[goodburbon]

Here's one for you....

How's a dyno that measures your power at the wheel work then? If we use your theory, it would fly right off the rollers and move forward....

They tie the car down. Are they going to tie the plane down? No? then it can take off.

I say again, it does not matter how fast you move the ground, the AIRSPEED is what gives a plane it's lift, and since the only thing between the treadmill and the plane is a set of free spinning wheels, the plane will roll off of the treadmill and down the runway as the engines pull it forward.

Open your mind a little bit.

hone: The clue phone is ringing, will you pick it up?

 

[shelbyluvv]

Wow, Finally a smart answer. Thank you 98XJ and Burbon!

 

[jeepboy381]

But if the plane is moving at the same speed forward as the treadmill is backwards you have no forward motion which means no lift right? Basically the plane will be standing still, how will it fly if it is standing still?

Are you guys as board at work as I am?

 

[98XJSport]

But if the plane is moving at the same speed forward as the treadmill is backwards you have no forward motion which means no lift right? Basically the plane will be standing still, how will it fly if it is standing still?

Are you guys as board at work as I am?

The aircraft doesn't have to overcome the speed of the treadmill like a car would because it's not getting it's power from the wheels, it's getting it elsewhere. And since the wheels aren't attached to any drive components, it won't "drag" the plane back with it.

And yes, horribly bored:helpme: