Mythbusters punk'd whole internet

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jagec

Lifer
Apr 30, 2004
24,442
6
81
Originally posted by: dullard
The belt can go infinitely fast and even then, THE PLANE WILL MOVE FORWARD. The wheels will not exert any significant force against the direction of the engine thrust.

Actually, with infinite speed/acceleration and indestructible wheels, it is possible for the treadmill to interact with the plane body via the angular momentum term. So you can keep the plane stationary, or even make it move backwards, until it runs out of fuel. You don't even need the friction term to assist you.

For any situation that's even close to realistic, both the friction and the angular momentum terms are so small as to be negligible, and the plane takes off.

Originally posted by: RapidSnail

In the treadmill = wheels scenario, the only way for there to be a net of zero would be if the plane was held stationary by a cable or something, right? There is no way for there to be net zero motion if the planes engines move and the treadmill = wheels, correct?

In any real scenario, true.

Originally posted by: Cerpin Taxt
There's nothing stopping the plane from moving forward, and thus accelerating the wheels, but once that happens you initiate an infinitely recursive self-oscillation where the treadmill must accelerate to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels...
Until you reach the speed at which the second-order effects like friction and angular momentum get large enough to actually affect the speed of the plane. At that point you CAN actually match the so-called "wheel speed" of the plane with the treadmill. Again...very unrealistic, but possible under certain constraints.

Maybe if we had a model plane with weak engines, very robust and heavy wheels, and a treadmill powered by a high-horsepower engine with a very fast response time, we could actually see the effect in real life. Otherwise, it's unlikely.
 

AlienCraft

Lifer
Nov 23, 2002
10,539
0
0
Originally posted by: Darwin333
Originally posted by: mordantmonkey
the thread is obviously doomed because the conveyor belt will have to keep moving faster and faster to keep the plane stationary in order to keep it from taking off.

Why would the conveyor belt's speed be a factor in the plane taking off? As long as the wheel/axle assembly can take the increased speed the speed of the conveyor has nothing to do with the speed of the air going over the wings and the wheels don't provide propulsion.
All that you need to understand. is bolded[./b]

 

waggy

No Lifer
Dec 14, 2000
68,143
10
81
good diragram that shows what i mean


you guys are getting hung up on wheel speed and convyer belt speed. it really does not matter.

the wheels do not provide any power. all power comes from the engines. no matter what the plane is going ot go foreword. foreword motion is going to provide lift. so the plane takes off.

 

Jeff7

Lifer
Jan 4, 2001
41,596
20
81
Originally posted by: jagec
They better not screw this one up, or we'll never hear the end of it.
It won't matter. Regardless of what they say, there'll still be debate.


Originally posted by: ITPaladin
huh?

The plane is going against the belt direction? I don't get what the test is.

Obvisously if there is no lift on the wings it will not fly if it is running opposite the way the belt is going.

:D
Here we go again.




Put a car on a treadmill. Start driving. As the wheels speed up, the treadmill speeds up. Result: car sits still. This is because the wheels provide the forward thrust onto the body of the car, as a result of pushing off of the (moving) ground.
Now strap a rocket engine onto the car and fire it up. The rocket provides forward thrust onto the body of the car independent of the motion of the ground. The ground (treadmill) can move at 10000kph, with the wheels spinning at millions of RPMs, but that won't matter - the rocket is what's providing the thrust. Thus, the car would be able to move forward.

Now turn that rocket car into a jet. The jet still moves forward, independent and regardless of the motion of the ground. Jet moves forward, air flows over the wings, plane takes off.


Mythbusters: good luck on this. OP: Thanks for the heads up. I'm wary of watching, for fear that they'll do something amateurish and botch it up, but hopefully they don't screw up. Physics will be pissed off at them if they say it won't take off.




Originally posted by: Cerpin Taxt
Originally posted by: RapidSnail
In the treadmill = wheels scenario, the only way for there to be a net of zero would be if the plane was held stationary by a cable or something, right? There is no way for there to be net zero motion if the planes engines move and the treadmill = wheels, correct?
Yes, but not because of some physical impossibility, but instead because of a rather trivial incoherency in the premise. In other words, there's nothing stopping the plane from moving forward, but as soon as it does, it is no longer true that "treadmill = wheels" with regard to speed. In still other words, it's impossible to create a feedback loop wherein the "speed of the treadmill = the speed of the wheels" under every circumstance.

There's nothing stopping the plane from moving forward, and thus accelerating the wheels, but once that happens you initiate an infinitely recursive self-oscillation where the treadmill must accelerate to match the new speed of the wheels, ....8
Get the idea? :)
Thus the treadmill approaches C, and turns to energy, thus causing an explosion more powerful than anything witnessed by humanity. The plane is converted into plasma and energy, which travel rapidly away from what was the treadmill, thus pieces of the plane do in fact take off.
Unless the treadmill collapses into a singularity due to the mass increase associated with extreme velocity. Then the plane wouldn't take off, as it'd be quickly sucked in and crushed.
 

smack Down

Diamond Member
Sep 10, 2005
4,507
0
0
Originally posted by: jagec
Originally posted by: dullard
The belt can go infinitely fast and even then, THE PLANE WILL MOVE FORWARD. The wheels will not exert any significant force against the direction of the engine thrust.

Actually, with infinite speed/acceleration and indestructible wheels, it is possible for the treadmill to interact with the plane body via the angular momentum term. So you can keep the plane stationary, or even make it move backwards, until it runs out of fuel. You don't even need the friction term to assist you.

For any situation that's even close to realistic, both the friction and the angular momentum terms are so small as to be negligible, and the plane takes off.

Originally posted by: RapidSnail

In the treadmill = wheels scenario, the only way for there to be a net of zero would be if the plane was held stationary by a cable or something, right? There is no way for there to be net zero motion if the planes engines move and the treadmill = wheels, correct?

In any real scenario, true.

Originally posted by: Cerpin Taxt
There's nothing stopping the plane from moving forward, and thus accelerating the wheels, but once that happens you initiate an infinitely recursive self-oscillation where the treadmill must accelerate to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels...
Until you reach the speed at which the second-order effects like friction and angular momentum get large enough to actually affect the speed of the plane. At that point you CAN actually match the so-called "wheel speed" of the plane with the treadmill. Again...very unrealistic, but possible under certain constraints.

Maybe if we had a model plane with weak engines, very robust and heavy wheels, and a treadmill powered by a high-horsepower engine with a very fast response time, we could actually see the effect in real life. Otherwise, it's unlikely.

:thumbsup:
 

smack Down

Diamond Member
Sep 10, 2005
4,507
0
0
Originally posted by: Jeff7
Originally posted by: jagec
They better not screw this one up, or we'll never hear the end of it.
It won't matter. Regardless of what they say, there'll still be debate.


Originally posted by: ITPaladin
huh?

The plane is going against the belt direction? I don't get what the test is.

Obvisously if there is no lift on the wings it will not fly if it is running opposite the way the belt is going.

:D
Here we go again.




Put a car on a treadmill. Start driving. As the wheels speed up, the treadmill speeds up. Result: car sits still. This is because the wheels provide the forward thrust onto the body of the car, as a result of pushing off of the (moving) ground.
Now strap a rocket engine onto the car and fire it up. The rocket provides forward thrust onto the body of the car independent of the motion of the ground. The ground (treadmill) can move at 10000kph, with the wheels spinning at millions of RPMs, but that won't matter - the rocket is what's providing the thrust. Thus, the car would be able to move forward.

Now turn that rocket car into a jet. The jet still moves forward, independent and regardless of the motion of the ground. Jet moves forward, air flows over the wings, plane takes off.


Mythbusters: good luck on this. OP: Thanks for the heads up. I'm wary of watching, for fear that they'll do something amateurish and botch it up, but hopefully they don't screw up. Physics will be pissed off at them if they say it won't take off.




Originally posted by: Cerpin Taxt
Originally posted by: RapidSnail
In the treadmill = wheels scenario, the only way for there to be a net of zero would be if the plane was held stationary by a cable or something, right? There is no way for there to be net zero motion if the planes engines move and the treadmill = wheels, correct?
Yes, but not because of some physical impossibility, but instead because of a rather trivial incoherency in the premise. In other words, there's nothing stopping the plane from moving forward, but as soon as it does, it is no longer true that "treadmill = wheels" with regard to speed. In still other words, it's impossible to create a feedback loop wherein the "speed of the treadmill = the speed of the wheels" under every circumstance.

There's nothing stopping the plane from moving forward, and thus accelerating the wheels, but once that happens you initiate an infinitely recursive self-oscillation where the treadmill must accelerate to match the new speed of the wheels, ....8
Get the idea? :)
Thus the treadmill approaches C, and turns to energy, thus causing an explosion more powerful than anything witnessed by humanity. The plane is converted into plasma and energy, which travel rapidly away from what was the treadmill, thus pieces of the plane do in fact take off.
Unless the treadmill collapses into a singularity due to the mass increase associated with extreme velocity. Then the plane wouldn't take off, as it'd be quickly sucked in and crushed.

Wow you couldn't be anymore wrong.

Where a force is applies doesn't matter. All that matters in the question is how you define the control of the treadmill. Put a car on a treadmill that matches the ground speed of the car and like the plane it will go forward but the speed at the wheel will be 2x the ground speed. Put a plane or car on a treadmill that matches the speed at the wheels and both will sit stationary.
 

her209

No Lifer
Oct 11, 2000
56,336
11
0
Originally posted by: mordantmonkey
Originally posted by: her209
Originally posted by: mordantmonkey
the thread is obviously doomed because the conveyor belt will have to keep moving faster and faster to keep the plane stationary in order to keep it from taking off.
WRONG!

The speed of the conveyor belt has no effect on the plane (in the original question) because the wheels are free spinning thus the plane WILL take off.
your assuming the wheels are perfectly frictionless?

it was a joke anyway. i was referencing the doomed thread and goading argument in the same breath

but if you insist...
if wheels have friction and belt can move infinitely fast then the plan will not move.
if they are frictionless wheels then the plan will take off regardless of whether the belt is magical or not.

however both belt and wheels being of this world, yes the plane will take off.

i never understood the problem with understanding this. it really boils down to... does the plane move, or can you stop a plane on wheels from moving by putting it on a treadmill. only in one strange outlandish situation is this possible.
I believe the original assumed the wheels were free-spinning, i.e. frictionless. Someone correct me if I'm wrong.
 

NanoStuff

Banned
Mar 23, 2006
2,981
1
0
Originally posted by: waggy
good diragram that shows what i mean


you guys are getting hung up on wheel speed and convyer belt speed. it really does not matter.

the wheels do not provide any power. all power comes from the engines. no matter what the plane is going ot go foreword. foreword motion is going to provide lift. so the plane takes off.

You're not about to understand this even if I tried my damn best trying to explain it, but it doesn't make a difference. If the wheels are tractionally bound to the ground, the plane's forward speed is directly proportional to the rotation of the wheels. If the conveyor belt compensates for the wheels, the plain goes nowhere, much like with a car. They have conveyor belts for testing cars, the cars don't take off, trust me.
 

smack Down

Diamond Member
Sep 10, 2005
4,507
0
0
Originally posted by: her209
Originally posted by: mordantmonkey
Originally posted by: her209
Originally posted by: mordantmonkey
the thread is obviously doomed because the conveyor belt will have to keep moving faster and faster to keep the plane stationary in order to keep it from taking off.
WRONG!

The speed of the conveyor belt has no effect on the plane (in the original question) because the wheels are free spinning thus the plane WILL take off.
your assuming the wheels are perfectly frictionless?

it was a joke anyway. i was referencing the doomed thread and goading argument in the same breath

but if you insist...
if wheels have friction and belt can move infinitely fast then the plan will not move.
if they are frictionless wheels then the plan will take off regardless of whether the belt is magical or not.

however both belt and wheels being of this world, yes the plane will take off.

i never understood the problem with understanding this. it really boils down to... does the plane move, or can you stop a plane on wheels from moving by putting it on a treadmill. only in one strange outlandish situation is this possible.
I believe the original assumed the wheels were free-spinning, i.e. frictionless. Someone correct me if I'm wrong.

It doesn't mater. Friction isn't the force to be concerned with anyway. As long as the wheels have mass they will apply a force against the airplane.
 

randay

Lifer
May 30, 2006
11,018
216
106
Originally posted by: jagec
At that point you CAN actually match the so-called "wheel speed" of the plane with the treadmill.

You can never match treadmill speed with wheel speed. The wheel will always be moving faster then the treadmill. x=y=x+y

 

mobobuff

Lifer
Apr 5, 2004
11,099
1
81
Originally posted by: NanoStuff
Originally posted by: waggy
good diragram that shows what i mean


you guys are getting hung up on wheel speed and convyer belt speed. it really does not matter.

the wheels do not provide any power. all power comes from the engines. no matter what the plane is going ot go foreword. foreword motion is going to provide lift. so the plane takes off.

You're not about to understand this even if I tried my damn best trying to explain it, but it doesn't make a difference. If the wheels are tractionally bound to the ground, the plane's forward speed is directly proportional to the rotation of the wheels. If the conveyor belt compensates for the wheels, the plain goes nowhere, much like with a car. They have conveyor belts for testing cars, the cars don't take off, trust me.

This guy isn't serious. Nobody argue with him.

 

her209

No Lifer
Oct 11, 2000
56,336
11
0
Originally posted by: NanoStuff
Originally posted by: waggy
good diragram that shows what i mean


you guys are getting hung up on wheel speed and convyer belt speed. it really does not matter.

the wheels do not provide any power. all power comes from the engines. no matter what the plane is going ot go foreword. foreword motion is going to provide lift. so the plane takes off.
You're not about to understand this even if I tried my damn best trying to explain it, but it doesn't make a difference. If the wheels are tractionally bound to the ground, the plane's forward speed is directly proportional to the rotation of the wheels. If the conveyor belt compensates for the wheels, the plain goes nowhere, much like with a car. They have conveyor belts for testing cars, the cars don't take off, trust me.
A car propels itself forward by exerting force on the ground via friction. A plane propels itself forward by exerting force on the air.
 

Cerpin Taxt

Lifer
Feb 23, 2005
11,940
542
126
Originally posted by: jagec
Originally posted by: Cerpin Taxt
There's nothing stopping the plane from moving forward, and thus accelerating the wheels, but once that happens you initiate an infinitely recursive self-oscillation where the treadmill must accelerate to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels, which in turn accelerates the wheels even more, which then demands that the treadmill accelerates to match the new speed of the wheels...
Until you reach the speed at which the second-order effects like friction and angular momentum get large enough to actually affect the speed of the plane. At that point you CAN actually match the so-called "wheel speed" of the plane with the treadmill. Again...very unrealistic, but possible under certain constraints.
I don't disagree, but I guess my point is that there must be an interval between the point where the disparity begins between the speeds of the wheels and treadmill, and the point where those second-order effects begin to affect the speed of the plane as you described. Thus, during the interval, the pre-conditions of the original problem are violated, making those preconditions impossible in operational terms. In other words, there isn't a real-world scenario where the preconditions would hold true at all times. Absent some qualifier in the original problem that the preconditions need not hold true during that interval, the preconditions are basically impossible.

EDIT TO ADD: More generally, since there are basically two ways to interpret the problem, and this scenario being so convoluted and obscure in comparison to the interpretation wherein the treadmill matches the speed of the plane, it should be obvious that the "wheels = treadmill" scenario is a misinterpretation of the problem, or even a mis-statement in the problem itself.
 

NanoStuff

Banned
Mar 23, 2006
2,981
1
0
Originally posted by: her209
Originally posted by: NanoStuff
Originally posted by: waggy
good diragram that shows what i mean


you guys are getting hung up on wheel speed and convyer belt speed. it really does not matter.

the wheels do not provide any power. all power comes from the engines. no matter what the plane is going ot go foreword. foreword motion is going to provide lift. so the plane takes off.
You're not about to understand this even if I tried my damn best trying to explain it, but it doesn't make a difference. If the wheels are tractionally bound to the ground, the plane's forward speed is directly proportional to the rotation of the wheels. If the conveyor belt compensates for the wheels, the plain goes nowhere, much like with a car. They have conveyor belts for testing cars, the cars don't take off, trust me.
A car propels itself forward by exerting force on the ground via friction. A plane propels itself forward by exerting force on the air.

Lovely theory, but it's easy to test it. If you look at a stationary plane, you will be shocked, it's actually stationary despite the planet revolving hundreds of kilometers an hour! My GOD, MAGIC! It's not rolling away!
 

DanTMWTMP

Lifer
Oct 7, 2001
15,908
19
81
Originally posted by: NanoStuff
Originally posted by: her209
Originally posted by: NanoStuff
Originally posted by: waggy
good diragram that shows what i mean


you guys are getting hung up on wheel speed and convyer belt speed. it really does not matter.

the wheels do not provide any power. all power comes from the engines. no matter what the plane is going ot go foreword. foreword motion is going to provide lift. so the plane takes off.
You're not about to understand this even if I tried my damn best trying to explain it, but it doesn't make a difference. If the wheels are tractionally bound to the ground, the plane's forward speed is directly proportional to the rotation of the wheels. If the conveyor belt compensates for the wheels, the plain goes nowhere, much like with a car. They have conveyor belts for testing cars, the cars don't take off, trust me.
A car propels itself forward by exerting force on the ground via friction. A plane propels itself forward by exerting force on the air.

Lovely theory, but it's easy to test it. If you look at a stationary plane, you will be shocked, it's actually stationary despite the planet revolving hundreds of kilometers an hour! My GOD, MAGIC! It's not rolling away!

LOL thanks for the laughs nanostuff. your sarcasm is making my tummy hurt..ooo.
 

Cerpin Taxt

Lifer
Feb 23, 2005
11,940
542
126
Originally posted by: NanoStuff
Originally posted by: her209
Originally posted by: NanoStuff
Originally posted by: waggy
good diragram that shows what i mean


you guys are getting hung up on wheel speed and convyer belt speed. it really does not matter.

the wheels do not provide any power. all power comes from the engines. no matter what the plane is going ot go foreword. foreword motion is going to provide lift. so the plane takes off.
You're not about to understand this even if I tried my damn best trying to explain it, but it doesn't make a difference. If the wheels are tractionally bound to the ground, the plane's forward speed is directly proportional to the rotation of the wheels. If the conveyor belt compensates for the wheels, the plain goes nowhere, much like with a car. They have conveyor belts for testing cars, the cars don't take off, trust me.
A car propels itself forward by exerting force on the ground via friction. A plane propels itself forward by exerting force on the air.

Lovely theory, but it's easy to test it. If you look at a stationary plane, you will be shocked, it's actually stationary despite the planet revolving hundreds of kilometers an hour! My GOD, MAGIC! It's not rolling away!

That's due to inertia, not force delivered to the plane through the axles.
 

NanoStuff

Banned
Mar 23, 2006
2,981
1
0
Originally posted by: Cerpin Taxt
Originally posted by: NanoStuff
Originally posted by: her209
Originally posted by: NanoStuff
Originally posted by: waggy
good diragram that shows what i mean


you guys are getting hung up on wheel speed and convyer belt speed. it really does not matter.

the wheels do not provide any power. all power comes from the engines. no matter what the plane is going ot go foreword. foreword motion is going to provide lift. so the plane takes off.
You're not about to understand this even if I tried my damn best trying to explain it, but it doesn't make a difference. If the wheels are tractionally bound to the ground, the plane's forward speed is directly proportional to the rotation of the wheels. If the conveyor belt compensates for the wheels, the plain goes nowhere, much like with a car. They have conveyor belts for testing cars, the cars don't take off, trust me.
A car propels itself forward by exerting force on the ground via friction. A plane propels itself forward by exerting force on the air.

Lovely theory, but it's easy to test it. If you look at a stationary plane, you will be shocked, it's actually stationary despite the planet revolving hundreds of kilometers an hour! My GOD, MAGIC! It's not rolling away!

That's due to inertia, not force delivered to the plane through the axles.

Ok, so place an unmoving plane on top of a conveyor belt and start up the conveyor belt. In fantasy land perhaps the plane would remain in place, but in the real world the plane would start moving back with the conveyor belt.

My theory is that magical fairies are moving the plane backwards with the conveyor belt, but suddenly disappear when the plane starts up it's engine. What's your theory?
 

smack Down

Diamond Member
Sep 10, 2005
4,507
0
0
Originally posted by: her209
Originally posted by: NanoStuff
Originally posted by: waggy
good diragram that shows what i mean


you guys are getting hung up on wheel speed and convyer belt speed. it really does not matter.

the wheels do not provide any power. all power comes from the engines. no matter what the plane is going ot go foreword. foreword motion is going to provide lift. so the plane takes off.
You're not about to understand this even if I tried my damn best trying to explain it, but it doesn't make a difference. If the wheels are tractionally bound to the ground, the plane's forward speed is directly proportional to the rotation of the wheels. If the conveyor belt compensates for the wheels, the plain goes nowhere, much like with a car. They have conveyor belts for testing cars, the cars don't take off, trust me.
A car propels itself forward by exerting force on the ground via friction. A plane propels itself forward by exerting force on the air.

It doesn't mater. Repeat after me it doesn't mater if where the force is applied. In both case the force that moves the body is being applied to the body of the car or airplane. Think of the wheels on the car just pushing on the car.

Edit: Friction can NEVER apply a force that moves an a object it is always in the opposite direction.
 

Zenmervolt

Elite member
Oct 22, 2000
24,514
44
91
Originally posted by: Jeff7
Thus the treadmill approaches C, and turns to energy, thus causing an explosion more powerful than anything witnessed by humanity. The plane is converted into plasma and energy, which travel rapidly away from what was the treadmill, thus pieces of the plane do in fact take off.
Unless the treadmill collapses into a singularity due to the mass increase associated with extreme velocity. Then the plane wouldn't take off, as it'd be quickly sucked in and crushed.

Best. Answer. Ever.

ZV
 

ultimatebob

Lifer
Jul 1, 2001
25,134
2,450
126
Originally posted by: DanTMWTMP
Originally posted by: lyssword
The plane takes off

/thread

oh wait..it airs in 1.5 hrs. haha.

I still got $5 on them NOT being able to take off. Never underestimate the Mythbuster's ability to defy Physics with harsh Reality!

 

smack Down

Diamond Member
Sep 10, 2005
4,507
0
0
Originally posted by: ultimatebob
Originally posted by: DanTMWTMP
Originally posted by: lyssword
The plane takes off

/thread

oh wait..it airs in 1.5 hrs. haha.

I still got $5 on them NOT being able to take off. Never underestimate the Mythbuster's ability to defy Physics with Reality!

Physics and reality really have nothing to do with the question. It is all in how you define the control system on the treadmill. Make it match the ground speed the plane, or car takes off. Make it match the wheel speed plane or car stays put. Any idiot should be able to understand that.
 

waggy

No Lifer
Dec 14, 2000
68,143
10
81
Originally posted by: NanoStuff
Originally posted by: waggy
good diragram that shows what i mean


you guys are getting hung up on wheel speed and convyer belt speed. it really does not matter.

the wheels do not provide any power. all power comes from the engines. no matter what the plane is going ot go foreword. foreword motion is going to provide lift. so the plane takes off.

You're not about to understand this even if I tried my damn best trying to explain it, but it doesn't make a difference. If the wheels are tractionally bound to the ground, the plane's forward speed is directly proportional to the rotation of the wheels. If the conveyor belt compensates for the wheels, the plain goes nowhere, much like with a car. They have conveyor belts for testing cars, the cars don't take off, trust me.

wow..

there is a huge diffrence between a CAR and a plane. you put a car on the traedmill yes it wont take off. why? ITS A FUCKING CAR. the power is generated by the wheels.

With a plane its in the engines that produce thrust. with thrust the foreword mementom has nothing to do with the wheels. so you can ignore them. its going to move.

the 3rd law proves that..
 

RapidSnail

Diamond Member
Apr 28, 2006
4,257
0
0
Originally posted by: Cerpin Taxt
Originally posted by: RapidSnail
In the treadmill = wheels scenario, the only way for there to be a net of zero would be if the plane was held stationary by a cable or something, right? There is no way for there to be net zero motion if the planes engines move and the treadmill = wheels, correct?
Yes, but not because of some physical impossibility, but instead because of a rather trivial incoherency in the premise. In other words, there's nothing stopping the plane from moving forward, but as soon as it does, it is no longer true that "treadmill = wheels" with regard to speed. In still other words, it's impossible to create a feedback loop wherein the "speed of the treadmill = the speed of the wheels" under every circumstance.

...


Get the idea? :)

:thumbsup:


Originally posted by: Jeff7
Thus the treadmill approaches C, and turns to energy, thus causing an explosion more powerful than anything witnessed by humanity. The plane is converted into plasma and energy, which travel rapidly away from what was the treadmill, thus pieces of the plane do in fact take off.
Unless the treadmill collapses into a singularity due to the mass increase associated with extreme velocity. Then the plane wouldn't take off, as it'd be quickly sucked in and crushed.

Excellent. :thumbsup::laugh: