OT Plane on a conveyer belt

[Brian Blazer]

The plane has wheels so if the belt is going 5mph and the plane is going 5mph in the opposite direction, the wheels are going 10mph. The first 5mph of the 10mph makes the plane stationary, the second 5mph (5 mph in the opposite direction) pushes the plane forward.

Neat little brain teaser.

 

[Terry Keeley]

Ya but:

"the conveyor has a system that tracks the speed of the plane and matches it exactly in the opposite direction" B)

 

[Charles Perdue]

Guys,
Unless the conveyor can completely negate the thrust from the engines (which it can't without applying the brakes or something gives out), then the plane will take off. As soon as you hit the throttle, the plane wil start moving in. The conveyor will start moving in the opposite direction and the wheels wil rotate at twice the speed they should, given the planes ground speed. If the plane has a take-off speed of, say, 200MPH, then at the moment the plane reaches that speed, the conveyor will be moving at 200MPH in the opposite direction, having no effect on the plane at all, other the wheels, which will be rotating as if the plane were going 400MPH. As it's been stated by a few who GET IT, unless the tires or wheel bearings give out, the plane will fly.

Any further debate is purely acedemic......... Don's probably right, though.

Thanks. Brad.

Titan Racing Components

BlackJack Hydros

YEP, YEP and YEP.

 

[LH7018]

I didn't know the jet engines pushed the plane on the runway. I always thought there was a huge transmission with lots of gearboxes, shafts, and linkages that went to all the wheels, and all those black tire marks on the runway tarmac were from young pilots doing high RPM neutral drops and massive landing gear burnouts when the air traffic controllers weren't looking. :blink:

 

[Ray Sametz]

You know the water is getting hard in most places, when you get 3 pages of this. It's going to be a long winter. :lol: :lol: :lol:

 

[NITROSNIFER]

Ok after reading 3 pages of this my question is "whats a plane??"" :huh: :huh: :huh:

 

[barry]

This answer was given to me by a friend who studies arero engineering and is about to enter the air force.

yes! the plane will take off because as it is propelled forward the only Resistance on the plane is the weight on the wheels and as the conveyer tracks the speed of the plane, the wight of the plane is decreased due to lift and less resistance on the wheels as it gets faster!

 

[tnrcboatracer]

Last I heard, airplanes were,'t powered by their wheels.........

But if you put a horizontal wicker cylinder above a bicycle and power it with a chain from the wheels, will the bicycle fly?

 

[moparbarn]

Last I heard, airplanes were,'t powered by their wheels.........
But if you put a horizontal wicker cylinder above a bicycle and power it with a chain from the wheels, will the bicycle fly?

tried that when i was a youngster, no, it won't fly :lol: :lol: .

 

[Wesleys Custom Graphics]

This answer was given to me by a friend who studies arero engineering and is about to enter the air force.
yes! the plane will take off because as it is propelled forward the only Resistance on the plane is the weight on the wheels and as the conveyer tracks the speed of the plane, the wight of the plane is decreased due to lift and less resistance on the wheels as it gets faster!

The origional question stated that no matter how fast the plane went on the conveyer, the conveyer matched it's speed, thus no forward movement and no lift. The conveyer and plane would continue to increase speed to infinity.

 

[Scott Norris]

OK, I see where you are coming from.
Yes the plane will eventually fly if the conveyor is long enough. I was kind of thinking a lot shorter conveyor and that the engines were powered enough only to compensate for the 100mph conveyor and the friction of the moving components.

Do I have your respect again?

Only if you say something really useful and intelligent. Jump into Martys Engine Timing Thread and give us all the numbers on your Record Engines.

 

[Rokieboater]

So a stationary plane with no head wind will take off into flight???????

 

[moparbarn]

james, this IS all your doing! look at the sh*t you stirred up! good job . keep the spoon handy, keep stirring the pot.

 

[Preston_Hall]

OK, I see where you are coming from.
Yes the plane will eventually fly if the conveyor is long enough. I was kind of thinking a lot shorter conveyor and that the engines were powered enough only to compensate for the 100mph conveyor and the friction of the moving components.

Do I have your respect again?

Only if you say something really useful and intelligent. Jump into Martys Engine Timing Thread and give us all the numbers on your Record Engines.

The best advice I can give is to not listen to 95% of all that technical stuff you here. Go with what you see working the best on your boat and make it better. Get a good motor and pipe, set your boat up and make adjustments with calipers, and work with Andy on props. If your boat is lagging then a good prop from Andy can give you 5-10 mph easy. Andy seems to understand props better than anybody.

 

[Don Ferrette]

This answer was given to me by a friend who studies arero engineering and is about to enter the air force.
yes! the plane will take off because as it is propelled forward the only Resistance on the plane is the weight on the wheels and as the conveyer tracks the speed of the plane, the wight of the plane is decreased due to lift and less resistance on the wheels as it gets faster!

The origional question stated that no matter how fast the plane went on the conveyer, the conveyer matched it's speed, thus no forward movement and no lift. The conveyer and plane would continue to increase speed to infinity.

DING! DING! DING! DING!

 

[Scott Norris]

OK, I see where you are coming from.
Yes the plane will eventually fly if the conveyor is long enough. I was kind of thinking a lot shorter conveyor and that the engines were powered enough only to compensate for the 100mph conveyor and the friction of the moving components.

Do I have your respect again?

Only if you say something really useful and intelligent. Jump into Martys Engine Timing Thread and give us all the numbers on your Record Engines.

The best advice I can give is to not listen to 95% of all that technical stuff you here. Go with what you see working the best on your boat and make it better. Get a good motor and pipe, set your boat up and make adjustments with calipers, and work with Andy on props. If your boat is lagging then a good prop from Andy can give you 5-10 mph easy. Andy seems to understand props better than anybody.

OK............I respect you again.

 

[tnrcboatracer]

This is a typical reference frame error. The plane is not powered by it's wheels, it is powered by either a propellor or a turbine relative to the air. The thrust is placed into the air, not the conveyor. The conveyor can match the planes speed in reverse, that just means that the wheels are turning twice as fast as the plane is moving relative to the air. No matter how fast the conveyor moves, the plane still moves relative to the air. Hence, it will take off. This is a classic mis-direction brain teaser. The one caveat is that if the friction in the wheel bearings/tires create drag equal or greater than the thrust, then the plane cannot accelerate to take off. Of course that would be moot, as the wheels/tires would catch fire, and there would be a big boom fed by aviation fuel.

Enough already!! How did I let myself be dragged into this??????????

Oh, and yes, theortically thew bicycle would take off, but it would sink back down as the forward speed decreased after lift off. Now, if you put a propellor on there to keep it moving forward after lift off, then yes it would stay up as long as it is moving forward. This effect is easily explained with vortex theory and circulation. **** that Bernoulli.........................

PS, I used to be an Aereospace Engineer specializing in advanced composites...........I'm now a Automotive Machining Process Engineer.

Have a good day, I'm off to go cross eyed analyzing CMM data............................Can't wait to go home and work on boats

 

[Nigtmare]

Not only it can take off.but it can also land on conveyor.take a look at this.


The Motor home at this case is the Conveyor!! :blink: :blink:

Nick

 

[moparbarn]

jon, you're right about the bicycle-i landed in the swimming pool every time i rode it off the roof of my parent's house !

 

[Charles Perdue]

This is a typical reference frame error. The plane is not powered by it's wheels, it is powered by either a propellor or a turbine relative to the air. The thrust is placed into the air, not the conveyor. The conveyor can match the planes speed in reverse, that just means that the wheels are turning twice as fast as the plane is moving relative to the air. No matter how fast the conveyor moves, the plane still moves relative to the air. Hence, it will take off. This is a classic mis-direction brain teaser. The one caveat is that if the friction in the wheel bearings/tires create drag equal or greater than the thrust, then the plane cannot accelerate to take off. Of course that would be moot, as the wheels/tires would catch fire, and there would be a big boom fed by aviation fuel.
Enough already!! How did I let myself be dragged into this??????????

Oh, and yes, theortically thew bicycle would take off, but it would sink back down as the forward speed decreased after lift off. Now, if you put a propellor on there to keep it moving forward after lift off, then yes it would stay up as long as it is moving forward. This effect is easily explained with vortex theory and circulation. **** that Bernoulli.........................

PS, I used to be an Aereospace Engineer specializing in advanced composites...........I'm now a Automotive Machining Process Engineer.

Have a good day, I'm off to go cross eyed analyzing CMM data............................Can't wait to go home and work on boats

Up to this point, I was sure that the plane would take off. After rereading the question I realized

that it only said that the plane moved. It did not say forward or backward. If it took off backward

that would make a welliva hreck. HIC :lol: