Plane on a Treadmill

[brianhos]

Re: CyBookie - Plane on a Treadmill

That is very disturbing. Please don't get a job where you serve the public's interests.

Are you serious? This is the most idiotic thing I have ever heard. The plane with have no wind moving across its wings, no wind = no lift = no flight. That plane will 100% NOT take off. We need an event on it, cause I am going all in, and begging Jeremy for a $1M credit loan to go all in on that!

 

[cmoneyr]

Re: CyBookie - Plane on a Treadmill

Are you serious? This is the most idiotic thing I have ever heard. The plane with have no wind moving across its wings, no wind = no lift = no flight. That plane will 100% NOT take off. We need an event on it, cause I am going all in, and begging Jeremy for a $1M credit loan to go all in on that!

Oh for god's sake...

You're a bookie, make an event, and you better go all in.

 

[brianhos]

Re: CyBookie - Plane on a Treadmill

Oh for god's sake...

You're a bookie, make an event, and you better go all in.

But we have a rule about making bookie events where the outcome is already known before hand.

 

[cmoneyr]

Re: CyBookie - Plane on a Treadmill

But we have a rule about making bookie events where the outcome is already known before hand.

Hilarity.

 

[cmoneyr]

Re: CyBookie - Plane on a Treadmill

Seriously though, you should make an event. I would definitely go all in that the plane will take off with ease.

 

[brianhos]

I must not understand the question. The plane is on the treadmill, so it has a land speed of say 400 mph, but has an air speed of 0? And you all think that it is all of a sudden going to take off? You are all creating this entire thread to make fun of me aren't you.

 

[isuno1fan]

Assumption 1: The treadmill is a powered treadmill (i.e., it has a motor) and can spin the tread at a rate as fast as the rate the airplane's wheels could be spun at max thrust while on an stationary surface (ground).

Assumption 2: The treadmill tread (i.e., motor) can match the spin rate of the airplane's wheels instantly and without delay.

Assumption 3: Plane and treadmill are both stopped/not moving to start with (i.e., 0 thrust from plane's engine and no power applied to tread by treadmill motor).

Assumption 4: No physical limits on hardware (e.g. motor of treadmill will not blow up, wheels will not explode, etc.)

Result: Plane will never move -> No airflow over wing surface -> PLANE WILL NOT TAKE OFF.

 

[Wesley]

Where is the moral turpitude of this group?. This event should have no odds to post - it is predetermined.

On the other hand, if Brian loses, give him back his credits. This is not an event. It is a brain teaser. Not sure who would even rule on the answer at this point. God?

 

[jbhtexas]

I must not understand the question. The plane is on the treadmill, so it has a land speed of say 400 mph, but has an air speed of 0? And you all think that it is all of a sudden going to take off? You are all creating this entire thread to make fun of me aren't you.

Did you read my little bungee cord experiment?

 

[cmoneyr]

Re: CyBookie - Plane on a Treadmill

Think of it this way. The treadmill has absolutely no bearing on anything in this situation, it is a complete red herring to make it a trick question. The prop/jet of a plane produces thrust, this thrust has an equal and opposite reaction, that being the plane moving forward. The fact that the ground is moving means nothing, the wheels of a plane are for all intents and purposes free spinning with only small amounts of friction. As the plane moves forward from the thrust, the free spinning wheels will compensate and turn at whatever speed is necessary given the speed of the treadmill, in this case twice as fast. The wheels, and therefore the treadmill has no affect on the outcome of the plane.

The only way the treadmill makes a plane not take off is if the planes jet engines turn an axle attached to the wheels which in turn makes the plane move forward. This is of course not the case with airplanes. I think jbhtexas posted the scenario of the tractor and the bungee cord. That is the best way I've seen to illustrate this point. The bungee will always pull the tractor forward at the same rate, the only thing the treadmill affects his how many rotations the wheels make on its way forward. Now replace tractor with airplane and bungee cord with jet engine and we have our answer.

Now make that bet and we can go all in.

 

[chadm]

Everyone agrees it takes forward movement with air moving over the wings to lift the plane.

The question that is in dispute is does the plane move forward.

If the plane only adds enough thrust to stay even with the friction in the tires to tread and the bearing on the wheels it will not move forward and will not lift.

If the plane is allowed to add enough thrust to move forward on a long treadmill it will have no problem getting enough speed to get lift.

 

[ISUKyro]

My God This Thread Is Still Open - Somebody Kill Me!!!

 

[tim_redd]

It's harder to make arguments in this thread when you've been drinking...

 

[cmoneyr]

Re: CyBookie - Plane on a Treadmill

A plane produces thrust correct?

And this thrust causes a plane to move forward correct?

A planes wheels do not transfer this thrust to the ground correct?

A planes wheels are free spinning (minus small amounts of friction) correct?

So where exactly does the treadmill have any bearing on the force of the jet engine? The treadmill can move twice as fast as the plane for all it matters, the wheels would just spin 4/8/10 times faster as it moved forward at whatever speed the engines produced.

 

[ISUKyro]

It's harder to make arguments in this thread when you've been drinking...

It wasn't that easy sober

 

[superfan]

Re: CyBookie - Plane on a Treadmill

Think of it this way. The treadmill has absolutely no bearing on anything in this situation, it is a complete red herring to make it a trick question. The prop/jet of a plane produces thrust, this thrust has an equal and opposite reaction, that being the plane moving forward. The fact that the ground is moving means nothing, the wheels of a plane are for all intents and purposes free spinning with only small amounts of friction. As the plane moves forward from the thrust, the free spinning wheels will compensate and turn at whatever speed is necessary given the speed of the treadmill, in this case twice as fast. The wheels, and therefore the treadmill has no affect on the outcome of the plane.

While I'm convinced the issue comes from the ambiguity of the question? (i.e. - In what frame of reference do we have "equal" speed - inertial or relative to the wheel.) I would like to ask...

Under this logic, if the treadmill is moving and the engines are producing no thrust, does the plane stay in the same place? If the treadmill has no effect on the plane...

 

[cmoneyr]

Re: CyBookie - Plane on a Treadmill

While I'm convinced the issue comes from the ambiguity of the question? (i.e. - In what frame of reference do we have "equal" speed - inertial or relative to the wheel.) I would like to ask...

Under this logic, if the treadmill is moving and the engines are producing no thrust, does the plane stay in the same place? If the treadmill has no effect on the plane...

I think the idea is that if a plane produces enough thrust to move it forward at 50mph, then the treadmill would be moving at 50mph in the opposite direction. The thing is that it doesn't matter, and the treadmill is only added into the equation because it's confusing.

If the treadmill was moving but the plane was producing no thrust then the wheels of the plane would be spinning at whatever speed the treadmill was, but the plane will not be moving forward. Now, keep the same situation, but turn on the jet engine, the plane will now move forward. The treadmill will increase it's speed to match the planes, but all that will accomplish is making the wheels spin faster.

Seriously though, jbhtexas' example was probably the best I've read for this brain teaser, if you can't see an answer after that then you may never.

 

[isuno1fan]

Everyone agrees it takes forward movement with air moving over the wings to lift the plane.

The question that is in dispute is does the plane move forward.

If the plane only adds enough thrust to stay even with the friction in the tires to tread and the bearing on the wheels it will not move forward and will not lift.

If the plane is allowed to add enough thrust to move forward on a long treadmill it will have no problem getting enough speed to get lift.

Bingo...

 

[cmoneyr]

Bingo...

Bingo what? That was his name-o?

 

[CloneFan65]

It seems everyone agrees that the plane needs to move forward to become airborn, so the real question is, will the plane move forward. My understanding is this... it's the same as if I were to stand on a treadmill with roller skates and a jet pack on my back. Then the question becomes, is it possible for the treadmill to spin fast enough to prevent me from moving forward? Since the jetpack propels me using friction with the air and not the ground (i.e. treadmill) I'm guessing I would still move forward.