A plane is standing on a runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. 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).
The question is:
Will the plane take off or not?
Note: SRV1 is disqualified! ;)
No.
If they're moving at the same speed, but opposite directions, there is no more wind to create lift than if it were sitting still. (I assume since they are moving at the same speed that you mean the wheels of the plane are moving, not the plane)
No......needs airflow over the wings......
Regardless of the thrust, if the plane is not moving forward, it won't get any lift.
YES!
Is it the Harrier Jump Jet? ;)
Yes
NO, Ill get technical
For an airplane to fly, it must always engage in a tug of war between the opposing forces of lift versus weight and thrust versus drag.
For a moment, think of an airplane moving from right to left and the flow of air moving from left to right. The weight or force due to gravity pulls down on the plane opposing the lift created by air flowing over the wing. Thrust is generated by the propeller (http://"http://proptypes.htm") and opposes drag caused by air resistance to the airplane. During take off, thrust must be greater than drag and lift must be greater than weight so that the airplane can become airborne.
For landing thrust must be less than drag, and lift must be less than weight
Well, two people have it right, but for the wrong reason/no justfication.
Well who has it right and what is the reason.
The answer is yes. The conveyer belt only matches the speed of the plane. It is not trying to increase the treadmill speed to keep the plane's velocity to 0.
So, if the plane is moving at 5mph, the conveyer is moving at 5mph in the opposite direction. The only thing slowing the airplane is the friction in the wheels. This is easily overcome by the thrust from the engines.
Judging by the fact that before he posted that 2 people were right.. there was 5 answers.. 3 were no, 2 were yes ;)
Plus he said the wrong reason/no justification
4th quarter got it right but wrong reason
stuntmannick got it right but didn't justify
I should be sherlock holmes ;)
well then the question was deceitful. because you said the sensor tracks the plane's
speed wouldn't the thrusters have something to do with the 'speed' so then the calculations to the track would make match that even when the thrusters are on.
I think it's a trick question.. nobody ever said that the plain actually tried taking off. The question states taht the plane is
standing on the runway.. then it just simply states 2 facts.. that the track moves one way and the plan moves the other. IT never stated that they are actually in that process of moving just that they can.
It's like a car that's not turned on, it moves forwards or in reverse. but it's not actually in the process of doing so at that particular moment, its just what the car can do.
Yeah, that's why I used this little disclaimer.
"(I assume since they are moving at the same speed that you mean the wheels of the plane are moving, not the plane)"
If the plane is physically 'moving', then the wheels will be moving at twice the speed of the treadmill. You need to be more clear, proffessor. ;)
There is a simpler explanation: The plane is not driven by its wheels, so turning the treadmill in the opposite direction will not slow the plane. Since the plane would travel at the normal speed that it would be travelling for a given amount of thrust, the plane would take off normally. The landing gear would take a beatinig, though - those wheels would be spinning FAST!!!
I was stuck by that as well as I figured it would eventually shoot itself off the end and take off....but it said it matched the speed, which I assumed to mean forward velocity.
Anyway.....good question though.
The plane will take off ( I cheated :P )
edit: Holy cow, there were so many posts between the moment I clicked on the add reply and the moment I posted.
well, if you want to get technical, it is a trick question. Using only statements provided in the riddle itself the answer is "no". The plane is clearly standing. The riddle states that the plane "moves" but lots of things move, but is it or is it not currently "moving", no, the riddle does not state so.
also, i don't like this trickery with the use of velocity and speed, and it doesn't provide a proper refrence with relation to speed, if it is the "speed" of the plane in relation to the "tread mill" or if it is the "speed" of the plane in relation to a fixed point, of if it is the "velocity" of the plane in relation to the air around it.
so no, this plane doesn't take off, it goes in circles in the mixed up universe it is stuck in, while the pasengers slowly go crazy in a land of symantic hell they find themselves in, to-may-to to-mah-to!!! AAAAHHHHHHHHHH
:rollin:
Regardless, I was right all along.
Mythbusters is doing Airplane on a Treadmill on tonight's show.
The internets are sure to explode afterwards.
Indeed. Getting ready to watch it now. :D
I say yes, it will take off. The treadmill only has an effect on the ground speed. But planes don't put their power to the ground. The treadmill/conveyor will have minimal effect.
EDIT: The real question for me is: Will the plane take off before the landing gear fails from excessive speed as it will be rolling twice as fast as intended.
BUSTED!!
(dur....)
Ya know, there's only one thing that determines whether or not a plane flies .. if there is enough airflow over the wings to create enough lift. The question is (intentionally?) devoid of enough information to answer properly.
The real question is, who keeps bringing this up? I'd much rather discuss canned hamburgers...
http://www.techeblog.com/index.php/tech-gadget/picture-cheeseburger-in-a-can-becomes-reality
Sorry those saying the question didn't have enough info, it did, as I got it by answer 2 or three on the first page.
Since the wheels of the plane are free spinning (not powering the plane) the belt under it has nothing to do with it... the belt could not spin fast enough to cause enough drag on bearings to stop that plane at all. I don't even think it could slow it.