Airplane on a Conveyor conundrum

[Chillitt]

well work this one out.

if there is no force acting on the wheel, then it would roll for an infinate time. it would never stop.
since this doesnt happen, then there MUST be a force acting. its simple science.

i pushed my toy car along the ground, and it went a few feet and stopped.
by your science, it should have carried on going, and going and never stopped until it hit a wall.

Did you see the bit where I said friction in the Bearing??
Did you? Well thats why your toy car hasn't battered all the paint off the skirting board.
And just to clarify, the bearings on the wheels of aircraft are usually better made than the bearings on toy cars, so the effect is much much less.

By you logic if you use the same amount of energy to push your toy car along the ground, as you use to pull the piece of paper out from under it, the car will move the same distance each time... try it...

[Slugsie]

For an approximately correct question.

Radical!!



Stop it you lot, I'm trying to change a rear wheel bearing on Linda's truck, but keep having to come indoors for the latest installment. Its taken over an hour just get the halfshaft out!!

Going to be doing that tonight. Are you using the 'Shade Tree' method?

[Chillitt]

einstein also states that if you know every factor, you can calculate every outcome. somewhere.

Yes, but where?

[TonyN]

Going to be doing that tonight. Are you using the 'Shade Tree' method?

I have press and correct special tools.

Unfortunatly, I don't seem to have wheel bearing and seal!! Doh!!!

[Slugsie]

why would you want to specify the age and what not of the pilot? that has no relevence here,.

you clearly not understanding that you missed to provide a serious factor in your equasion, and because of this, you get different results and wonder why.

einstein also states that if you know every factor, you can calculate every outcome. somewhere.

When you model a system, you have to do a degree of simplification, otherwise the model is as complex as the system, and doesn't help matters. A part of the real system is the pilot, and a part of the pilot is his age. But the age isn't relevant, so it was removed from the model.

I removed other parts of the system for the model I originally posited because I didn't think they would be relevant for people to work out the truth of the system. When it became obvious that this wasn't the case, I provided a clarification to the model to remove this over simplification. You have continued to ignore that clarification. So your arguments are pointless.

[Slugsie]

I have press and correct special tools.

Unfortunatly, I don't seem to have wheel bearing and seal!! Doh!!!

Damn, I have the wheel bearing and seal (just arrived - Thanks Roughtrax), but no press and correct tools.

[Slugsie]

OK, we have about an hour to get this thread to 600 posts!

[dieselboy]

WHAT IS THIS FORCE THAT THE CONVEYOR PLACES ON THE PLANE?
HOW, ON THE FACE OF GODS GREEN EARTH CAN THE CONVEYOR GRIP A ROLLING WHEEL????

here is more proof, there will be a force on the wheels through the conveyor.

in space, when the shuttle or similar flies to the moon, or wherever, it has no thrust once its in space. all engines are off.

it uses its engines to bring it to speed. and then switches them off. this is because there is no force in space. therefore the craft does not slow down.

space probes on their way to distant planets dont have any drive, or forward force. so they also do not slow down.

[MattF]

A part of the real system is the pilot, and a part of the pilot is his age. But the age isn't relevant, so it was removed from the model.

Actually, just on a pedantic note again, if you plonked, for example, a 2 year old in the pilots seat, that would have a pretty damned big bearing on the experiment.

[dieselboy]

By you logic if you use the same amount of energy to push your toy car along the ground, as you use to pull the piece of paper out from under it, the car will move the same distance each time... try it...

WELL DONE!
now you have proved yourself wrong!
when you pull out the piece of paper, and you push the car, what happens!? the car doesnt move!

therefore the plane doesnt move and it WILL NOT TAKE OFF

[MattF]

space probes on their way to distant planets dont have any drive, or forward force. so they also do not slow down.

A vacuum has no relevance to a planet with an atmosphere.

[Slugsie]

Actually, just on a pedantic note again, if you plonked, for example, a 2 year old in the pilots seat, that would have a pretty damned big bearing on the experiment.

True, but I did state that the pilot was normally capable of flying the plane, so I had that angle covered.

[MattF]

True, but I did state that the pilot was normally capable of flying the plane, so I had that angle covered.

Just checking.

[Slugsie]

WELL DONE!
now you have proved yourself wrong!
when you pull out the piece of paper, and you push the car, what happens!? the car doesnt move!

therefore the plane doesnt move and it WILL NOT TAKE OFF

Err, no. If you sit your car on the floor, and give it a good firm push so that it rolls off - then it moves. Now, put the paper underneath it, and pull the paper whilst at the same time providing the same amount of push as you did first time, the car will move forward.

If the only 'push' you are providing is the absolute minimum needed to overcome the friction then no, it won't move. But you aren't providing that amount of push. Just like the aircraft isn't trying to remain stationary, it is actively trying to take-off.

[dieselboy]

A vacuum has no relevance to a planet with an atmosphere.

it does when your making a point that without a force acting on anything, that object will keep doing what its doing
until a force acts on it.