Brain-teaser: Will this plane fly?

[ho1ywars]

Originally Posted by OnTheWingsOfCrossfire

I find it interesting that the whole flow of the thread on the discovery site is basically summed up through all of my posts, lol.

And, to show that I at least have some grounding in what I'm trying to help explain, I present a visual aid:

They give this award to one student a year for the graduating class (class of '00 was 800+ students).

I'm not trying to say that I'm in any way an expert at anything or that I'm necessarily more right or wrong than anyone else, just simply that I have a firm grasp of the concepts I'm attempting to explain.

Oh, and I'm going to sleep now.

just.. hold on one second.. eh.. know i have a mad science plaque sitting around here somewhere..

dont need to be OUTSTANDING in science, just have to understand how powerfull plane engines are, and how little friction the wheels create during take off.

alright seriously, im sick of this crap, whos got a freaking plane, haha

[ho1ywars]

i presented a visual aid of the experiment itself.. and people still question it. ****, half of the people posting in this thread have no idea whats going on in the first place.. lol.

oh, and i did not read the whole tread, but i find it funny that at the end of the thread, everyone on that forum(discovery) came to an agreement that the plane would fly.

[dolphinS4]

Originally Posted by noreaga0221

Go run on the treadmill with a jetpack on. See if you can keep yourself from being displaced.

[QUOTE]This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."


You can not assume things not stated in the problem. Doesn't matter how fast the plane goes, the conveyer goes the same exact speed. Fact.

Can't assume its a jet.
Can't assume tires loose traction.
Can't assume engines are powerfull enough to do....
Can't assume anything but known physical forces acting on the body.

For every assumption, there's an equally valid assumption that says the exact opposite. We're will that get us?
You have to stick to known and proven forces and their consequences.

[ho1ywars]

[QUOTE=dolphinS4]

This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."


You can not assume things not stated in the problem. Doesn't matter how fast the plane goes, the conveyer goes the same exact speed.

he is comparing it correctly, he is trying to help you understand that running, and driving a car, are totaly different then an airplane. read back in the post, it explains why, i am tired of restating it over and over.

[ho1ywars]

[QUOTE=dolphinS4]

This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."


You can not assume things not stated in the problem. Doesn't matter how fast the plane goes, the conveyer goes the same exact speed. Fact.

Can't assume its a jet.
Can't assume tires loose traction.
Can't assume engines are powerfull enough to do....
Can't assume anything but known physical forces acting on the body.

For every assumption, there's an equally valid assumption that says the exact opposite. We're will that get us?
You have to stick to known and proven forces and their consequences.

if a planes engines arnt big enough to over come the little bit of friction that the bearings create during take off, the it is clearly not big enough for the plane to take flight, period, with or without the belt.

[2point4DSM]

Originally Posted by dolphinS4

Doesn't matter how fast the plane goes, the conveyer goes the same exact speed.

Let's ASSume the plane goes 5 mph and the conveyor goes 5mph in the opposite direction. Still the plane is moving forward in order to go 5mph. If it were not moving forward 5 mph there is no way for it to go 5 mph since the wheels are not connected to the engines by a transmission. The engines on the plane are acting directly on the air around it and not on the conveyor. The conveyor is just there to spin the wheels backwards.

If the plane is moving forward and accelerating then it gets air movement around its wings and it flies.

[dolphinS4]

[QUOTE=ho1ywars]

Originally Posted by dolphinS4

he is comparing it correctly, he is trying to help you understand that running, and driving a car, are totaly different then an airplane. read back in the post, it explains why, i am tired of restating it over and over.

I've read all the post.
Thanks.
Some of his post are proven worthless on the first day of Dynamics 101.

[ho1ywars]

[dolphinS4]

[QUOTE=ho1ywars]

Originally Posted by dolphinS4

if a planes engines arnt big enough to over come the little bit of friction that the bearings create during take off, the it is clearly not big enough for the plane to take flight, period, with or without the belt.

You clearly don't get it

[2point4DSM]

Ironic, isn't it....

[ho1ywars]

[QUOTE=dolphinS4]

Originally Posted by ho1ywars

You clearly don't get it

lol, obviously i do get it, considering i have four other people on this forum that agree with me, and are thinking the same way, and a whole other forum(discovery) that believes the plane will fly. i have yet to find a forum that states the plane wont fly.

[dolphinS4]

Originally Posted by 2point4DSM

Let's ASSume the plane goes 5 mph and the conveyor goes 5mph in the opposite direction. Still the plane is moving forward in order to go 5mph. If it were not moving forward 5 mph there is no way for it to go 5 mph since the wheels are not connected to the engines by a transmission. The engines on the plane are acting directly on the air around it and not on the conveyor. The conveyor is just there to spin the wheels backwards.

If the plane is moving forward and accelerating then it gets air movement around its wings and it flies.

This is not a correct evaluation of the problem.

The exact moment the plane moves forward, be it from the engines, someone pushing it, or a great gust of wind, the belt reacts with the exact speed in the opposite direction. There is no lag or deviation from the speed of the belt and the wheels. Since the wheels and the plane, (engine, wheels, seats, pilot, the whole plane) are one unit, any force acting on one affects the whole unit, reguardless of how they are connected. Thrust created by the engines does not just act upon the engine structure, but the whole plane since they are connected.

[Silver04STi]

The question doesn't state that the belt is keeping the aircraft stationary, just that it is matching its speed in the opposite direction

[dolphinS4]

Originally Posted by Silver04STi

The question doesn't state that the belt is keeping the aircraft stationary, just that it is matching its speed in the opposite direction

Lol!!

Thats the whole premise of the problem. If it said the plane was stationary, would you say the plane would fly?

[Silver04STi]

Originally Posted by dolphinS4

Lol!!

Thats the whole premise of the problem. If it said the plane was stationary, would you say the plane would fly?

exactly

[Silver04STi]

this is why we are sitting here arguing over this

[dolphinS4]

Originally Posted by Silver04STi

exactly

No, I am actually asking you a question.

If the problem states the plane is stationary from the movement of the belt, would you conclude that the plane would fly or wouldn't fly?

[dolphinS4]

Originally Posted by Silver04STi

this is why we are sitting here arguing over this

No, we are arguing over the fact that you guys are assuming a whole lot of senarios that the problem does not state.

[Silver04STi]

Originally Posted by dolphinS4

No, I am actually asking you a question.

If the problem states the plane is stationary from the movement of the belt, would you conclude that the plane would fly or wouldn't fly?

if it held the plane stationary it would not fly....but you guys are assuming it is holding the plane stationary

[Silver04STi]

The plane would attain takeoff speed no matter what surface it is sitting on conveyor belt, ice, coveyer belt made of ice. It is like saying if the plane were sitting on ice, it wouldn't go anywhere it would just sit there and spin it wheels, not true. The plane accelerates relative to the air, NOT TO THE GROUND.