Are we dealing purely with forward/backward momentum here? If you are going forwards with the unicycle, and the rocket pack is moving you forwards aswell then unless the treadmill counters your speed exactly you will go forward.
conveyor belt and plane answered at last ??
- Thread starter big-all
- Start date
Are we dealing purely with forward/backward momentum here? If you are going forwards with the unicycle, and the rocket pack is moving you forwards aswell then unless the treadmill counters your speed exactly you will go forward.
Sponsored Links
It has nothing to to do with Newtons law or Grasshoppers for that matter.
It's a trick Joe under stand the above quote taken from the original post.
For what it's worth the conveyor could be stopped, if the plane matches it's speed it still isn't taking off.
Million lb thrust and rockets to mars make no different.
Interesting how very few 'experts' on this thread are measuring speed in knots rather then mph 
It's a nonsense question. As soon as the aircraft moves forward the wheels will be moving faster than the conveyor and the experiments rules are broken.
It's a nonsense question. As soon as the aircraft moves forward the wheels will be moving faster than the conveyor and the experiments rules are broken.
Sponsored Links
This is the original question....
An aircraft is standing on a very long runway that can move (a conveyor belt). The aircraft moves in one direction, while the conveyor belt moves in the opposite direction. This conveyor belt has a control system that tracks the aircraft's wheels speed and tunes the speed of the conveyor belt to be exactly the same as the wheels, but in the opposite direction. There is no wind. The pilot begins to add thrust to the engines...
Will the plane ever take off?
An aircraft is standing on a very long runway that can move (a conveyor belt). The aircraft moves in one direction, while the conveyor belt moves in the opposite direction. This conveyor belt has a control system that tracks the aircraft's wheels speed and tunes the speed of the conveyor belt to be exactly the same as the wheels, but in the opposite direction. There is no wind. The pilot begins to add thrust to the engines...
Will the plane ever take off?
Well done Joe I think you just hit jackpot
The question is not invalid, it asks will the plane take off given the above conditions.
"No the plane will not take off"
No Joe, that is the question, you can't re-word it to suit or make your own rules.
The conveyor is travelling at 85mph and the wheels of the plane are doing exactly the same as the planes forward trust holds it in place.
If the wheels go slower the plane will go backwards, if the plane goes forward the wheels must be going faster than to belt to make ground.
Same as the tread mill, you can run on the spot at 5mph whereas if you run at 6mph and the belt travel is still 5mph you'll run off the end.
The conveyor is travelling at 85mph and the wheels of the plane are doing exactly the same as the planes forward trust holds it in place.
If the wheels go slower the plane will go backwards, if the plane goes forward the wheels must be going faster than to belt to make ground.
Same as the tread mill, you can run on the spot at 5mph whereas if you run at 6mph and the belt travel is still 5mph you'll run off the end.
- Joined
- 28 Oct 2005
- Messages
- 31,281
- Reaction score
- 1,997
- Country
You aint getting it. If the power is applied to the belt through the wheels then NEWTON'S THIRD LAW APPLIES at the WHEELS and what you say is true. However if the wheels are allowed to spin freely and the engines deliver thrust - THEN NEWTON'S THIRD LAW applies at the ENGINES. Fook all to do with the wheels. NEWTON'S THIRD LAW is LAW.
I'm not getting it
We all know what you are saying Joe, but it is not within the context of the question. The rules are laid down right or wrong, you must answer the question accordingly, not re-write it and quote space rockets, jumbo jets or even Newtons law.
Did you know that if you turn the plane round so it is facing the direction of the conveyor belt travel, at 85knots the plane will leave the ground and the wheels are not even turning and the engine is turned off.
We all know what you are saying Joe, but it is not within the context of the question. The rules are laid down right or wrong, you must answer the question accordingly, not re-write it and quote space rockets, jumbo jets or even Newtons law.
Did you know that if you turn the plane round so it is facing the direction of the conveyor belt travel, at 85knots the plane will leave the ground and the wheels are not even turning and the engine is turned off.
Sponsored Links
