I understand what everyone is saying BUT, what causes lift is the planes foward motion provided by the turbines that forces the air over the wings making the plane take off.

The wings are what causes lift not the turbines. If the plane is at a stand still in relation to the air around the wings (If it were on a treadmill) it will not take off. There is no air flow over the wings

Now lets picture a plane that is propelled by the wheels and not turbines...

On the treadmill it can operate just fine but wont take off.

Why?

NOT because the lack of a turbine but because of no air flow over the wings.

Now lets picture this same plane moving down the runway at the speed required for lift, the plane will take off.

Of course it wont stay airborne as it cannot maintain lift because when the wheels leave the ground obviously there is no more propulsion. This is why a turbine is required - to maintain being airborne.

The point of a turbine is to maintain the plane being airborn not to take off.

Take away the wings and no flight.

The fact of the matter is, in order for a plane to take off air is required to flow over the wings.

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Edit:

So are you guys going to tell me that the jet propulsion is what is required for lift? X amount of thrust ect ect...

What about non jet powered planes? Props.

They for sure dont make as much power as a turbine... but wait I thought that the turbine makes X thrust was required for the plane to take off...

NOPE. The propeller plane can take off just fine. Why? The same concept of AIR flowing over the wings.

Jet engines are just more powerful for more weight (commercial airlines) and to be faster these are not required to take off.

 

You are wrong, and don't understand how an airplane works.

The question is a trick question. The treadmill is a useless variable to confuse you.

Without the agonizing explanation of this scenario, watch Mythbusters on Wednesday at 9pm EST and you will get your answer.

Wings don't cause lift. Wings create lift. If you were to aim a turbine at a Mugen wing on the back of an s2000, the car would squat down, as the air pressure is pushing the back down.

Also, you forget that the wheels are not attached to anything, and are free spinning, which is very important to this question. The plane will move through the air regardless of the treadmill. The treadmill just causes a tiny bit of friction that is negligible against the power of the turbines.

Forget turbines, and concentrate on something simpler...a single propeller plane. If it is on a treadmill, the thrust generated by the propeller will create a pressure difference over/under the wings, and the plane would take off.

You need to think of a jet airplane as a controlled rocket. A rocket takes off at standstill (in any direction it's pointed) purely due to thrust. The plane has the same principle. The engines provide thrust.

A 747 takes off at approximately 157mph. According to your theory, a plane would take off standing still in a 157mph direct headwind, which of course, is not the case.

 

Hm maybe I am wrong, I dont know. Guess I will have to watch and find out!

 

man, some of you way over-complicate a really simple question lol.

What does the treadmill even have to do with the plane taking off? Might as well ask if a plane could take off on ice or crushed eggshells for all it matters.

 

haha, interesting topic. i guess the real question isn't can a plane take off on a treadmill, but more can the treadmill hold a plane in place and the answer is no because of the thrust.

hahaha, i think the trick in the question that everyone is misinterpreting is that when they think of a treadmill they think of a stationary object relative to the earth. but putting a plane on a treadmill is kind of useless isn't it?

to expand on the rollerblade on a treadmill example it would be like in jackass. how johnny knoxville had the roller skates with the bottle rockets attached. i guess if he was on a treadmill and holding onto the handrail he would be stationary. but as soon as someone lights those bottle rockets and he was still holding onto the railing his feet would fly up into the air as the skates got boosted.

 

Glad to see some people posting in the thread who get it

 

The problem is that people keep comparing the plane to some guy on a treadmill at the gym. The key thing here is that the guy at the gym on the treadmill is not moving, no matter what the indicator on the machine says. Stand on the ground next to him and shoot a radar gun at him...or better yet, use a gps unit...you will get 0mph...no matter how fast his legs are moving and how much he's sweating. And that is the valid way of measuring his speed...not by the indicator on the treadmill.

The reason this is valid is because to solve a problem like this, we have to take the treadmill's speed and the runner's (or plane's) speed from the same frame of reference. Taking the runner's speed in relation to the treadmill, and the treadmill's speed in relation to the ground, in not a valid way to solve a problem.

The point is, the plane will take off, the car will take off, the runner will take off. Because, in order for the treadmill to spin backwards, the plane/car/runner has to be moving forwards. That is a condition set forth in the riddle. A runner not moving while the treadmill is spinning does not meet this condition.

 

The plane/runner/whatever will move forward, no matter what, thus it will gain speed and take off.

Forget about the plane, lets say the question says the plane is on a 100 yard runway, that's a tread mill, which is followed by a normal asphault runway that is stationary.

Suppose the question asks "can the plane make it off the treadmill and onto the tarmac runway?"

The answer is yes because the jets will push the plane forward and no matter what the treadmill does to counter it the plane will still be able to move forward.

 

Nope, the car (or runner) won't take off. I'm sure the riddle meant "moving forward" in relation to the treadmill's direction, not to a fixed point on Earth. So a plane would take off, a runner or a car wouldn't. But I see your point. I guess the riddle is open to interpretation.

 

lol, wut?