think about this...

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Once again, the OP states that the conveyor does in fact matter. It presents a state where the conveyor and the wheels are moving at the same speed in opposite directions. You can't state that as a condition and then say "Well once you add thrust you can ignore that condition". Unless the OP actually said that, but it didn't, so I don't see how you can blame all these guys who read that and assume that the airspeed must be 0.

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I simply assumed since we were talking about a plane thrust would be a given condition of take off.

[CrazyEyez]

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I think (hopefully) everyone is beyond this point by now. The only question is, how retarded was the wording of the OP?

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- Riddle: does x + y = x?
- No.
- Yes it does! Just ignore y. Idiot.
- [img]/images/graemlins/frown.gif[/img]

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y = 0

duh

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goddamit I knew someone would say that. [img]/images/graemlins/grin.gif[/img]

[d10]

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I think (hopefully) everyone is beyond this point by now. The only question is, how retarded was the wording of the OP?

[/ QUOTE ]
- Riddle: does x + y = x?
- No.
- Yes it does! Just ignore y. Idiot.
- [img]/images/graemlins/frown.gif[/img]

[/ QUOTE ]

y = 0

duh

[/ QUOTE ]

You do realize that by admitting that 0 is the only possible value for Y in this equation, you're also saying that the only possible airspeed for a plane to be moving when it's wheels are rolling at the same speed as a conveyor its sitting on is moving in the opposite direction would be 0, right?

[TheMetetron]

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I mean seriously, he just said "I wasn't going to make you pay anyway."

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FWIW, I told some people on aim long ago that I had no intentions of taking half of my friends bankroll from him. Im just waiting for him to admit hes wrong.

[/ QUOTE ]

This is true.

Also, I think the man owes you $400.

[Oblivious]

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But the OP said there was a direct relationship between the wheels and the conveyor, so how do you say the wheels don't matter? The OP specifically states that it does matter.

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Because the conveyor doesn't matter either!!!!

The question, in the long run, comes down to: will a plane take off as it is designed to?

[/ QUOTE ]

Once again, the OP states that the conveyor does in fact matter. It presents a state where the conveyor and the wheels are moving at the same speed in opposite directions. You can't state that as a condition and then say "Well once you add thrust you can ignore that condition". Unless the OP actually said that, but it didn't, so I don't see how you can blame all these guys who read that and assume that the airspeed must be 0.

[/ QUOTE ]

You dont have to "ignore" the fact that the wheel and runway move/rotate at the same linear velocity. I present a case where the wheel and runway have infinite linear velocity as soon as the plane moves one smidgen forward. Who can claim that inifinity>infinity is false? Since we cant use infinity like a number in algebraic equations, it might be mathematically sound that the wheel has a finite displacement (lateral motion) and an infinite rotational motion, while the runway also has an infinite rotational motion. Since we cant define the rotational motions of the wheel or the conveyor, saying that they are equal isnt such an atrocity.

[Godfather80]

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I think (hopefully) everyone is beyond this point by now. The only question is, how retarded was the wording of the OP?

[/ QUOTE ]
- Riddle: does x + y = x?
- No.
- Yes it does! Just ignore y. Idiot.
- [img]/images/graemlins/frown.gif[/img]

[/ QUOTE ]

y = 0

duh

[/ QUOTE ]

You do realize that by admitting that 0 is the only possible value for Y in this equation, you're also saying that the only possible airspeed for a plane to be moving when it's wheels are rolling at the same speed as a conveyor its sitting on is moving in the opposite direction would be 0, right?

[/ QUOTE ]

This has been magical. Please, throw in some more physics words when you "unleash the fury", Patrick.

[jman220]

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The thing is, as stated in the original problem, the runway speeds up to compensate for the extra +x force.

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But that's the issue here, CAN the runway compensate for the thrust of the engines? Imagine the wheels are frictionless, and the conveyor belt is spinning backwards at 100 mph and the plane is just sitting there, engines at idle. The conveyor belt has no effect on the plane and therefore has no way to counteract the thrust of the plane.


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Yes but in that situation, for the air speed to be > 0, the speed of the wheels has to be > 100. The plane will take off, but the wheels and conveyor will not be going the same speed, therefor the conditions of the OP will not have been met. I'm still waiting for someone to explain where I'm wrong.

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You've mentioned this five times now, and you've been right each time, but they're just not understanding what you're saying of course. The plane can take off, for all the reasons stated already, but when it does take off, the wheels will be moving x mph faster than the conveyer belt, where x=the plane's velocity relative to the ground/air/whatever.

[LAGmaniac]

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But the OP said there was a direct relationship between the wheels and the conveyor, so how do you say the wheels don't matter? The OP specifically states that it does matter.

[/ QUOTE ]

Because the conveyor doesn't matter either!!!!

The question, in the long run, comes down to: will a plane take off as it is designed to?

[/ QUOTE ]

Once again, the OP states that the conveyor does in fact matter. It presents a state where the conveyor and the wheels are moving at the same speed in opposite directions. You can't state that as a condition and then say "Well once you add thrust you can ignore that condition". Unless the OP actually said that, but it didn't, so I don't see how you can blame all these guys who read that and assume that the airspeed must be 0.

[/ QUOTE ]

You dont have to "ignore" the fact that the wheel and runway move/rotate at the same linear velocity. I present a case where the wheel and runway have infinite linear velocity as soon as the plane moves one smidgen forward. Who can claim that inifinity>infinity is false? Since we cant use infinity like a number in algebraic equations, it might be mathematically sound that the wheel has a finite displacement (lateral motion) and an infinite rotational motion, while the runway also has an infinite rotational motion. Since we cant define the rotational motions of the wheel or the conveyor, saying that they are equal isnt such an atrocity.

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I agree and I mentioned before that it does work at infinity, but that doesn't bail out Ray or Patrick on some of their earlier assertions.

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You've mentioned this five times now, and you've been right each time, but they're just not understanding what you're saying of course. The plane can take off, for all the reasons stated already, but when it does take off, the wheels will be moving x mph faster than the conveyer belt, where x=the plane's velocity relative to the ground/air/whatever.

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The wheels will only move as fast as the force spinning them. In this case the conveyor belt. Remember they are independent of the movement of the plane. The plane can move and the wheels can stay still. The wheels can move and the plane can stay still. Both can move independently at the same time (as in this case).

[iversonian]

Same principle as reverse thrust on a jet engine. Draw a control volume around the apparatus and see where the change in momentum of the system comes from.