That analogy has absolutely nothing to do with your question :|. I'm out, it doesn't look like you're going to grasp this.

 

 

 

It doesn't look like YOU are going to grasp this.

scn64, yes the man would move forward if an additional force was added from behind. However, your original problem did not include such external forces. If you push the airplane forward so it moves faster than the threadmill can bring it back, then yes eventually with a big enough speed difference the plane would take off (assuming the threadmill has the required length for take off). Still, the plane would be moving when taking off, not standing still.

 

 

 

The jets on the plane are an external force as far as the treadmill is concerned.

The jets on the plane are an external force as far as the treadmill is concerned.

 

You're analogy has NOTHING to do with this situation. In your analogy, the skater is moving along the treadmill on its own power, just as the jet is. There is no man pushing the jet here.

 

 

 

It doesn't matter how it propels itself (for the 3rd time). I want you to understand this most simple of concept, for your sake.

i have an idea, lets just not run our airplanes on treadmills!

 

 

 

seriously though, according to physics unless your airplane is going faster then the tread mill, that plane is not going to go any where.

 

 

 

all that will happen is, it will sit there for maybe an hour or two, the tires will burn out and the plane will crash, or it will run out of gas, and fly off the tread mill

 

 

 

check, and mate

The jets on the plane are an external force as far as the treadmill is concerned.

 

You're analogy has NOTHING to do with this situation. In your analogy, the skater is moving along the treadmill on its own power, just as the jet is. There is no man pushing the jet here.

 

 

 

It doesn't matter how it propels itself (for the 3rd time). I want you to understand this most simple of concept, for your sake.

 

 

 

Why can't a car move forward when it's suspended in mid-air? Why CAN a jet plane move forward in the same situation?

Why can't a car move forward when it's suspended in mid-air? Why CAN a jet plane move forward in the same situation?

 

But you have to take in the fact that to get in the air, the plane has to reach the speed on the ground first. A plane is just a big car with wings until it gets enough forward velocity to take off. On this treadmill, it has no forward velocity, so no lift.

Why can't a car move forward when it's suspended in mid-air? Why CAN a jet plane move forward in the same situation?

 

But you have to take in the fact that to get in the air, the plane has to reach the speed on the ground first. A plane is just a big car with wings until it gets enough forward velocity to take off. On this treadmill, it has no forward velocity, so no lift.

 

 

 

Yes, but to gain that initial speed, even on the ground, the plane is relying on the same source of propulsion as it does when it's in the air, and that propulsion is not affected by ground movement.

Let us consider one important factor:

 

 

 

LetÃÆââââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢s say that we have a jet airplane (like a 747 for example) trying to take off on a giant runway sized treadmill. The treadmill, which turns in the opposite direction that the plane is facing, is capable of precisely matching the speed of the airplane. HereÃÆââââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢s a visual to bring it all together (not drawn to scale obviously )

 

 

 

Therefore, no matter how fast your turbines spin, the treadmill will match the speed of the jet. Therefore it can't move, therefore no lift is generated, therefore no flying hunks of metal.

Why are you argueing against physics? :wall: X a jazillion

this isn't the first time i've seen this thread on a forum. I'd like to point out, usually when this topic is posted, the OP intentionally ignores physics and logic and all sensible argument and instead uses irrelevant analogies to bolster his or her argument. like a troll. and this poster! wow, gj feeding the troll

Why are you argueing against physics? :wall: X a jazillion

 

 

 

When I first read this question I was on your side. I agreed with you. 50 pages of convincing later, I had changed my mind.

When I first read this question I was on your side. I agreed with you. 50 pages of convincing later, I had changed my mind.

 

 

 

There are no "sides". This is not a "debate". This is a matter of right or wong, possible or impossible. The plane isn't going to take off under those conditions, now matter how much hot air you blow out of yourself to convince yourself otherwise.

I'll give you ten books on how the American government is covering up the fact that the world is really flat. Plus, I'll throw in an essay on how NASA is really an advanced film editing studio, employed by the government to fake space missions. And, if you ignore the blatant stupidity, it'll be completely believable!

 

 

 

Fifty pages of forum posts is not a credible source.

This is a pretty common question asked, and I usually just ignore it. It seemed so obvious that the answer is no, it wouldn't take off. Now it seems so obvious the answer is it is possible, it depends entirely on how much friction is in the wheels. A stationary plane on a treadmill moving 50mph will move with the treadmill at 50 mph. The plane turns on its engines, and it will appear as if it is stationary, and the treadmill is just spinning the wheels. Throttle up, and it will be moving against the treadmill. The treadmill at this point makes little difference how fast it is going, depending on the friction of the planes wheels. The plane will move forward.

I don't see the need for insults.

I don't see the need for insults.

 

You'll have to excuse me, but after trying to explain it over 2 pages...

We're not insulting you.

I don't see the need for insults.

 

You'll have to excuse me, but after trying to explain it over 2 pages...

 

 

 

But your explanation is wrong, the plane will take off.

But your explanation is wrong, the plane will take off.

 

Oh come on, not another one... Indy, it just doesn't work.

You might possibly be aware that this argument is somthing like 2 years old??

 

 

 

Answer is no, forward thrust is needed to move air underneath the wings to lift the plane from the ground... the plain isn't actually moving while on the treadmill much in the same way a person isn't moving forward on a treadmill while running.. but instead of a jerky motion of a human the plane would simply roll on its wheels and not go anywhere...

 

 

 

at first glance it seems plausible, but its kinda like the question "since the earth is moving why don't we come down on a different spot when we jump"

I don't see the need for insults.

 

You'll have to excuse me, but after trying to explain it over 2 pages...

 

 

 

Right or wrong, I feel the same way. I'm trying to explain it to you. Obviously, I don't have a giant treadmill, a jet plane, and the necessary equipment to get the treadmill to match the plane speed and attempt to prove what I'm saying. I accept that I could be wrong. But I have spun this around and around in my head and I still come to the conclusion that the plane would move forward.

Right or wrong, I feel the same way. I'm trying to explain it to you. Obviously, I don't have a giant treadmill, a jet plane, and the necessary equipment to get the treadmill to match the plane speed and attempt to prove what I'm saying. I accept that I could be wrong. But I have spun this around and around in my head and I still come to the conclusion that the plane would move forward.

 

I would have thought that after thinking over and over in your head, you'd be taking a step in the right direction.

LetÃÆââââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢s say that we have a jet airplane (like a 747 for example) trying to take off on a giant runway sized treadmill. The treadmill, which turns in the opposite direction that the plane is facing, is capable of precisely matching the speed of the airplane. HereÃÆââââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢s a visual to bring it all together (not drawn to scale obviously)

 

 

 

This is a pretty common question asked, and I usually just ignore it. It seemed so obvious that the answer is no, it wouldn't take off. Now it seems so obvious the answer is it is possible, it depends entirely on how much friction is in the wheels. A stationary plane on a treadmill moving 50mph will move with the treadmill at 50 mph. The plane turns on its engines, and it will appear as if it is stationary, and the treadmill is just spinning the wheels. Throttle up, and it will be moving against the treadmill. The treadmill at this point makes little difference how fast it is going, depending on the friction of the planes wheels. The plane will move forward.

 

 

 

when you turn on the jet engines the treadmill will increace its speeds to compecent for this

 

 

 

also anything else you think could over come this, you must realize, that any action you think you can take to over come to treadmill to gain lift, the tread mill is going to increase its speed to keep you at a stand still, it just doesn't work

LetÃÆââââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢s say that we have a jet airplane (like a 747 for example) trying to take off on a giant runway sized treadmill. The treadmill, which turns in the opposite direction that the plane is facing, is capable of precisely matching the speed of the airplane. HereÃÆââââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢s a visual to bring it all together (not drawn to scale obviously)

 

 

 

This is a pretty common question asked, and I usually just ignore it. It seemed so obvious that the answer is no, it wouldn't take off. Now it seems so obvious the answer is it is possible, it depends entirely on how much friction is in the wheels. A stationary plane on a treadmill moving 50mph will move with the treadmill at 50 mph. The plane turns on its engines, and it will appear as if it is stationary, and the treadmill is just spinning the wheels. Throttle up, and it will be moving against the treadmill. The treadmill at this point makes little difference how fast it is going, depending on the friction of the planes wheels. The plane will move forward.

 

 

 

when you turn on the jet engines the treadmill will increace its speeds to compecent for this

 

 

 

When the treadmill increases its speed that will merely cause the wheels on the plane to spin faster while the plane continues to move forward.

But your explanation is wrong, the plane will take off.

 

Oh come on, not another one... Indy, it just doesn't work.

 

 

 

It can work. I was in the exact same position as you the first 100 times I saw this topic. Couldn't believe anyone actually thinks the plane would take off. Now I am on the fence, sometimes it would take off and sometimes it wouldn't. It really depends on the interpretation of the question, thus there is no right answer.