Physics Puzzle

[tim west]

Lets say the wheel are now doing a 100mph, but the runway is also doing a 100mph in the opposite direction, the propulsion is holding the plane stationary, e.g. to stop it shooting backwards at a 100 mph

Thats where you are wrong, the plane wouldnt move backwards if you turned off the thrust the wheels are freespinning. they apply no friction to the axle to push it backwards. the plane is like its sitting on an iceflow therefore applying thrust would have moved it forwards not holding it static as you imply.

Don't be silly, the wheels are sat on the road, therefor if the road is doing 100mph the plane and anything will also do 100mph, by applying thrust you can stop the backward travel, but the guy stood in the middle of the runway would have to hang on like grim death

I assure you im not being silly, think of the tyres as one continuous loop if you cut that loop and lay it out flat on the runway to achieve the endless loop we'd have to stretch the now flat tyre to an infitessimal length . agreed?

now the tyre is attached as you say to the runway by the tyres traction agreed?

the tyre track will run off with the runway at the runway/conveyor speed agreed?

now look at the top surface of this tyre track, its extremely slippery has no friction and therefore the planes axle would just slip on it if pushed agreed?

apply the push with the thrust and hey presto the plane moves forward regardless of what the runway and tyre track are doing.

 

[doitall]

the mechanics of the equation, albeit theoretical and certainly not practical, do not, in ant shape or form take into account the engines' reaction to the AIR or its thrust upon it.

can you runway and wheel people not see that this force has NOT been countered?

where do you suppose this energy goes?

The energy is stopping the backward movement, or contering the speed of the surface to which the plane is stood on.

Do you agree that if the runway is doing 100mph anything in contact with the surface will also do 100mph, unless you apply force against it

 

[doitall]

I assure you im not being silly, think of the tyres as one continuous loop if you cut that loop and lay it out flat on the runway to achieve the endless loop we'd have to stretch the now flat tyre to an infitessimal length . agreed?

now the tyre is attached as you say to the runway by the tyres traction agreed?

the tyre track will run off with the runway at the runway/conveyor speed agreed?

now look at the top surface of this tyre track, its extremely slippery has no friction and therefore the planes axle would just slip on it if pushed agreed?

apply the push with the thrust and hey presto the plane moves forward regardless of what the runway and tyre track are doing.

So your saying the plane would move forward at speed against the rotation of the wheels.

Or the wheels are doing 100mph and the plane is doing 200mph

 

[Trazor]

I will ask you again. doitall.
If a plane comes into LAND on the conveyor, then according to your theory, the moment the plane touches the conveyor, it must stop INSTANTLY, as it can,t move forward.

Can you explain this....?

 

[doitall]

I will ask you again. doitall.
If a plane comes into LAND on the conveyor, then according to your theory, the moment the plane touches the conveyor, it must stop INSTANTLY, as it can,t move forward.

Can you explain this....?

Not quite, because you have weight and forward movement.

 

[tim west]

Do you agree that if the runway is doing 100mph anything in contact with the surface will also do 100mph

yes i agree with you doitall allowing for no slip between the tyres and runway of course it would but the bearings inside the wheel take away that contact and therefore the wheel is not attached directly to the plane(friction wise)its allowed to spin freely.

Ok think of another argument from your viewpoint, youd agree if i said that one revolution of the tyre would move the tread the circumferance of the tyre? yes?

youd also argue that the tyre would move that distance along the runways surface as they are bonded by the friction of the tyres to the runway?

whether that runway moves or not the tyre has moved a distance along the material of the runway

im just talking of the wheel at the moment nothing else

move two revolutions and the tyre will have run two circumferances along the runway yes?

with the runway moving:

now imagine that that distance is totally irrelevant to the axle of the planes airframe simply because the wheel freewheeled the axle saw no travel apart from the inside surface of the wheel skating over its surface without friction

if there was a sensor inside that bearing it would register that the wheel had indeed spun twice but the axle would have been stationary same as if you held the axle in your hand or a vice and with the other hand spun the wheel round and round the axle would be stationary but the wheel would have turned twice.

 

[Trazor]

I will ask you again. doitall.
If a plane comes into LAND on the conveyor, then according to your theory, the moment the plane touches the conveyor, it must stop INSTANTLY, as it can,t move forward.

Can you explain this....?

Not quite, because you have weight and forward movement.

So you accept the plane coming into land, will move forward on the conveyor then....?

 

[doitall]

The plane cannot travel farther than the turn of the wheel, unless it's plaining or skidding.

And the storm is getting quite bad so I'm logging off in a minute

 

[tim west]

The plane cannot travel farther than the turn of the wheel, unless it's plaining or skidding.

And the storm is getting quite bad so I'm logging off in a minute

but thats the whole point it is skidding internally

 

[doitall]

I will ask you again. doitall.
If a plane comes into LAND on the conveyor, then according to your theory, the moment the plane touches the conveyor, it must stop INSTANTLY, as it can,t move forward.

Can you explain this....?

Not quite, because you have weight and forward movement.

So you accept the plane coming into land, will move forward on the conveyor then....?

Yes because of the above which is additional power to taking off.

What would probably happen is the under carriage would collapse, and the plain would nose dive

 

[doitall]

The plane cannot travel farther than the turn of the wheel, unless it's plaining or skidding.

And the storm is getting quite bad so I'm logging off in a minute

but thats the whole point it is skidding internally

The plane doesn't skid during take off it rolls, or rolling as we tell the control tower

 

[tim west]

The plane cannot travel farther than the turn of the wheel, unless it's plaining or skidding.

And the storm is getting quite bad so I'm logging off in a minute

but thats the whole point it is skidding internally

The plane doesn't skid during take off it rolls, or rolling as we tell the control tower

not the plane, the axle inside the wheel is skidding

 

[Trazor]

 

[markie]

heres a puzzle you wont get,


whats 38 and 20 come too ?

 

[noseall]

heres a puzzle you wont get,


whats 38 and 20 come too ?

Barry White of course.