Mythbusters to take on "the plane and the treadmill" conundrum?

[smack Down]

Originally posted by: vizkiz
Smack Down, think about it this way.

First: THE TREADMILL MATCHES THE SPEED OF THE BODY OF THE PLANE, NOT THE WHEEL SPEED!

The bearings in the wheels reduce the friction passed onto the plane by a factor of 100 (a conservative figure). This would mean that for every combined 100mph the wheels spin (50 mph for the plane + 50mph for the treadmill = 100mph wheel speed) the plane and treadmill are moving, the wheel speed is actually only reduced by 1mph.

That would mean the plane has a forward motion of 99mph. Now, as the plan adds airspeed, the treadmill does so too.

The plane reaches 300mph, so the treadmill has now also accelerated to 300mph. The friction on the wheels themselves is 600mph, but the bearings reduce this by a factor of 100. Therefore, the belt is only actually reducing the plane speed through friction by 6mph.

The plane is still moving 294mph and can still take off.

Sure you can change the question to make the plane take off.

 

[vizkiz]

Originally posted by: smack Down

Originally posted by: vizkiz
Smack Down, think about it this way.

First: THE TREADMILL MATCHES THE SPEED OF THE BODY OF THE PLANE, NOT THE WHEEL SPEED!

The bearings in the wheels reduce the friction passed onto the plane by a factor of 100 (a conservative figure). This would mean that for every combined 100mph the wheels spin (50 mph for the plane + 50mph for the treadmill = 100mph wheel speed) the plane and treadmill are moving, the wheel speed is actually only reduced by 1mph.

That would mean the plane has a forward motion of 99mph. Now, as the plan adds airspeed, the treadmill does so too.

The plane reaches 300mph, so the treadmill has now also accelerated to 300mph. The friction on the wheels themselves is 600mph, but the bearings reduce this by a factor of 100. Therefore, the belt is only actually reducing the plane speed through friction by 6mph.

The plane is still moving 294mph and can still take off.

Sure you can change the question to make the plane take off.

There, you admitted the plane will take off.

Now, how long will it take for you to figure out that I did not change the question. The belt always matched the speed of the plane from the get-go.

If it matched wheelspeed, then the belt would actually move forward as the plane moved forward, to keep the wheel from moving. The belt moving backwards would not in fact be matching the wheelspeed, but it would be doubling the wheelspeed.

 

[smack Down]

Originally posted by: sao123
tHIS QUESTION IS FOR SMACKDOWN

If I put the exact same plane on the exact same treadmill, tie a rope to the front of the plane, and tie the other end to a cemented stationary pole at the front end of the treadmill, and lets assume the treadmill is moving backwards really really fast...

What happens?

a)The treadmill pulls so hard on the rope it breaks...
b)The plane sits there in place doing nothing...

Well if the plane is going to sit there before you tie the rope it is going to sit there after.

 

[BrownTown]

smack Down is a troll, he is just trying to get you people riled up because he gets off on that kinda of stuff, everyone knows he is wrong, saying it 100 more times isn't gonna help anyone but the Troll.

 

[smack Down]

Originally posted by: BrownTown
smack Down is a troll, he is just trying to get you people riled up because he gets off on that kinda of stuff, everyone knows he is wrong, saying it 100 more times isn't gonna help anyone but the Troll.

No one has proved me wrong in this thread. Just a bunch of fools claiming the wheels don't matter because the engines have a lot of thrust. If you wish to prove the wheels don't mater show that the force on the plane is not proportional to the speed of the wheels or one of it derivatives.

 

[vizkiz]

Originally posted by: smack Down

Originally posted by: BrownTown
smack Down is a troll, he is just trying to get you people riled up because he gets off on that kinda of stuff, everyone knows he is wrong, saying it 100 more times isn't gonna help anyone but the Troll.

No one has proved me wrong in this thread. Just a bunch of fools claiming the wheels don't matter because the engines have a lot of thrust. If you wish to prove the wheels don't mater show that the force on the plane is not proportional to the speed of the wheels or one of it derivatives.

If the belt was there to keep the wheels from moving, it would move forward, to stop the wheels from rolling as the plane progressed forward.

It does not though, the belt tries to stop the forward motion of the plane by moving backwards.
The wheels VASTLY reduce the amount of friction passed onto the plane to a point where it does not matter. The wheels are essentially a buffer, they are there to keep the plane safe from the movement of the ground beneath it. They do nothing but spin freely with whatever they may come into contact with.

 

[vizkiz]

Bueller? Bueller? Bueller?

 

[vizkiz]

His light's on, but nobody's home :laugh:

 

[spidey07]

vizkiz,

I think you need to understand acceleration before you throw stones.

 

[vizkiz]

Originally posted by: spidey07
vizkiz,

I think you need to understand acceleration before you throw stones.

I understand acceleration perfectly fine. The fact of the matter is, the plane is accelerating through the AIR. The free-moving wheels touching the ground make an absolute minimal difference on the speed of the plane.

 

[sao123]

Originally posted by: smack Down

Originally posted by: sao123
tHIS QUESTION IS FOR SMACKDOWN

If I put the exact same plane on the exact same treadmill, tie a rope to the front of the plane, and tie the other end to a cemented stationary pole at the front end of the treadmill, and lets assume the treadmill is moving backwards really really fast...

What happens?

a)The treadmill pulls so hard on the rope it breaks...
b)The plane sits there in place doing nothing...

Well if the plane is going to sit there before you tie the rope it is going to sit there after.

and what would happen if the engine wasnt running?

 

[spidey07]

Originally posted by: vizkiz

Originally posted by: spidey07
vizkiz,

I think you need to understand acceleration before you throw stones.

I understand acceleration perfectly fine. The fact of the matter is, the plane is accelerating through the AIR. The free-moving wheels touching the ground make an absolute minimal difference on the speed of the plane.

How so? Can't happen in this fictious scenario. As worded the treadmill has infitite acceleration relative to the plane. Sure impossible in the real world and breaks physics (divide by zero), but holds true here as stated in the scenario.

That's pretty much what you can boil it down to, either you take it word for word or you change the problem.

 

[vizkiz]

Originally posted by: spidey07

Originally posted by: vizkiz

Originally posted by: spidey07
vizkiz,

I think you need to understand acceleration before you throw stones.

I understand acceleration perfectly fine. The fact of the matter is, the plane is accelerating through the AIR. The free-moving wheels touching the ground make an absolute minimal difference on the speed of the plane.

How so? Can't happen in this fictious scenario. As worded the treadmill has infitite acceleration relative to the plane. Sure impossible in the real world and breaks physics (divide by zero), but holds true here as stated in the scenario.

That's pretty much what you can boil it down to, either you take it word for word or you change the problem.

How about this one. Retract the wheels and throw a Buick chained to the plane onto the treadmill. The Buick, of course, will be in neutral. This is because the wheels on the plane are free-moving, the wheels on the Buick also must be free moving.

Now, does the plane still move forward, or does the dragging Buick cause it to slow down to a complete stop?

 

[Rogodin2]

The only way that a plane won't take off is IF the friciton generated by it's contact points (landing gear, floats, skiis) during it's movement forward is equal to or greater than the thrust of its engines/engine. The question presupposes that the band belt can move at the same speed as the wheels even it the plane has flaps down with WOT (this will prevent the plane from taking off NOT the wheels/skis/floats). So-you guys would have to make a physics equation with the the thrust (like torque but measured differently because were talking about air-not surface area) and the friction. Thrust can overcome gravity, that's why a harrier is able to take off vertically.

The ONLY way this would keep the plane from flying is if the belt was connected to a reverse thrust machine-like a big turbine or multiple props-if the reverse thruster could pull enough air in the opposite direction to compensate then the plane wouldn't take off.

But you guys arguing that wheel friction can overcome thrust are idiotic.

Rogo

 

[spidey07]

Originally posted by: Rogodin2
The only way that a plane won't take off is IF the friciton generated by it's contact points (landing gear, floats, skiis) during it's movement forward is equal to or greater than the thrust of its engines/engine. The question presupposes that the band belt can move at the same speed as the wheels even it the plane has flaps down with WOT (this will prevent the plane from taking off NOT the wheels/skis/floats). So-you guys would have to make a physics equation with the the thrust (like torque but measured differently because were talking about air-not surface area) and the friction. Thrust can overcome gravity, that's why a harrier is able to take off vertically.

The ONLY way this would keep the plane from flying is if the belt was connected to a reverse thrust machine-like a big turbine or multiple props-if the reverse thruster could pull enough air in the opposite direction to compensate then the plane wouldn't take off.

But you guys arguing that wheel friction can overcome thrust are idiotic.

Rogo

That's what the fly offers are having trouble grasping. This can't be done with analogies. Only taking the problem word for word can your reach to correct conclusion. It essentially breaks physics...the problem that is.

In your harrier example I will just blow air downward on it to prevent it from lifting, and I will do so with infinite force and acceleration.

 

[smack Down]

Originally posted by: sao123

Originally posted by: smack Down

Originally posted by: sao123
tHIS QUESTION IS FOR SMACKDOWN

If I put the exact same plane on the exact same treadmill, tie a rope to the front of the plane, and tie the other end to a cemented stationary pole at the front end of the treadmill, and lets assume the treadmill is moving backwards really really fast...

What happens?

a)The treadmill pulls so hard on the rope it breaks...
b)The plane sits there in place doing nothing...

Well if the plane is going to sit there before you tie the rope it is going to sit there after.

and what would happen if the engine wasnt running?

Then the treadmill would be off and again the plane will just sit there.

 

[bobdelt]

this is so stupid... dont you need the wind to create lift?

all it would do is make the wheels spin and the plain wont move... retarded.

 

[Bill Brasky]

Originally posted by: bobdelt
this is so stupid... dont you need the wind to create lift?

all it would do is make the wheels spin and the plain wont move... retarded.

But if the engines are on and creating thrust, then the plane will move forward regardless of what the treadmill is doing.

 

[Rogodin2]

Planes fly regardless of surface contact Spidey. That was my point. The friction created by any contact - if it doesn't overcome the thrust - will not prevent the plane from taking off. The only variable in the proposition was the speed of the treadmill-it assumes equally on both sides of the physics analogy. The plane WILL take off even with the invalid proposition-thrust is a great force.

Rogo

 

[smack Down]

Originally posted by: Zaitsev

Originally posted by: bobdelt
this is so stupid... dont you need the wind to create lift?

all it would do is make the wheels spin and the plain wont move... retarded.

But if the engines are on and creating thrust, then the plane will move forward regardless of what the treadmill is doing.

Wrong the treadmill is by definition of the problem appling a force equal to the thrust of the plane and keeping it stationary.

 

[Bill Brasky]

Lets just sticky this so we don't have to see it every two months.

 

[Mrvile]

lol @ this thread

Any time this subject is brought up it turns into this mess.

Basically, if the plane's wheels have no friction and the treadmill has no friction, the plane will take off. Assuming that it is a jet, of course.

The turbines propel the plane independent of the wheels.

As the plane moves forward, the treadmill speed will quickly approach infinity. As will the plane's wheel speed (they are not motorized). But since there is no friction, the treadmill has no affect on the actual plane itself and it will still be able to move forward.

Here's an example...imagine yourself on a treadmill with a rope in your hands (secured somewhere out in the distance) and rollerskates on your feet. The skates are frictionless (as they should be) as is the treadmill. As the treadmill speed approaches infinity, so do your skate's wheels. But since they are both frictionless, nothing happens and you are still able to pull yourself forward with the rope.

 

[Rogodin2]

What is the friction that Rockets must overcome-gravity. How much thrust is needed to propel a rocket?

*S*

I'm a humaities major for christ's sake and you guys are still arguing?

The Harrier would need to have it's thruster above water to not take off-it's not solid, but that varible wasn't introduced.

Rogo

 

[Mrvile]

Originally posted by: smack Down

Originally posted by: Zaitsev

Originally posted by: bobdelt
this is so stupid... dont you need the wind to create lift?

all it would do is make the wheels spin and the plain wont move... retarded.

But if the engines are on and creating thrust, then the plane will move forward regardless of what the treadmill is doing.

Wrong the treadmill is by definition of the problem appling a force equal to the thrust of the plane and keeping it stationary.

You, sir, are wrong.

 

[Mrvile]

Originally posted by: Rogodin2
What is the friction that Rockets must overcome-gravity. How much thrust is needed to propel a rocket?

*S*

I'm a humaities major for christ's sake and you guys are still arguing?

The Harrier would need to have it's thruster above water to not take off-it's not solid, but that varible wasn't introduced.

Rogo

Yeah but the thing with the plane and the treadmill is that the plane's wheels and the planes thrusters are completely independent of each other (unlike the harrier and the ground/water).