Well, maybe not exponentially but the treadmill would have to be able to achieve the same speed as a plane in flight, which the bearings probably wouldn’t bear.
[quote]beebuddy wrote:
…
What would actually happen in scenario #2 would be something like the speed of the treadmill increasing exponentially until the wheel bearings blew. It would probably happen almost instantly, but the plane would move forward slightly in that split second and then look like the plane in the pic.
[photo]14296[/photo]
Well, maybe not exponentially but the treadmill would have to be able to achieve the same speed as a plane in flight, which the bearings probably wouldn’t bear.[/quote]
Unless the treadmill bearings blew first.
[quote]Donut62 wrote:
Zap Branigan wrote:
beebuddy wrote:
Zap Branigan wrote:
Why would anyone even think it would? I don’t get it at all.
If you read my other post, in scenario #1 the wheels would simply spin at twice the speed that the plane needs to take off because the thrust comes from the prop/jet and not the wheels. It would take off just fine.
Scenario #2 is nonsense.
I was only considering scenario 2. The whole thing is nonsense.
Can a plane overcome a negative force and take off? Yes.
Can a plane remain motionless relative to the ground and atmosphere (like a runner on a treadmill) and take off? No.
Draw a free body diagram of an airplane on a treadmill. Consider that the engines move the plane in relation to the atmosphere, not the ground, and you will see that the only force acting against the plane from the running treadmill is the friction in the wheel bearings. There is no connection between the engine propulsion and the wheel speed. The plane takes off, the wheels just spin twice as fast. Of course, the tires are not rated for that type of wheel speed and would probably explode, but we’ll say they don’t.[/quote]
I get it, I just thought he was discussing a treadmill of infinite speed and variablity as in scenario 2. As long as we are doing something ridiculous we should go all the way.
[quote]Zap Branigan wrote:
Donut62 wrote:
Zap Branigan wrote:
beebuddy wrote:
Zap Branigan wrote:
Why would anyone even think it would? I don’t get it at all.
If you read my other post, in scenario #1 the wheels would simply spin at twice the speed that the plane needs to take off because the thrust comes from the prop/jet and not the wheels. It would take off just fine.
Scenario #2 is nonsense.
I was only considering scenario 2. The whole thing is nonsense.
Can a plane overcome a negative force and take off? Yes.
Can a plane remain motionless relative to the ground and atmosphere (like a runner on a treadmill) and take off? No.
Draw a free body diagram of an airplane on a treadmill. Consider that the engines move the plane in relation to the atmosphere, not the ground, and you will see that the only force acting against the plane from the running treadmill is the friction in the wheel bearings. There is no connection between the engine propulsion and the wheel speed. The plane takes off, the wheels just spin twice as fast. Of course, the tires are not rated for that type of wheel speed and would probably explode, but we’ll say they don’t.
I get it, I just thought he was discussing a treadmill of infinite speed and variablity as in scenario 2. As long as we are doing something ridiculous we should go all the way.
[/quote]
In that case let’s give the plane frictionless bearings, in which case it would take off because the ground beneath might as well be “aether.”
[quote]beebuddy wrote:
Well, maybe not exponentially but the treadmill would have to be able to achieve the same speed as a plane in flight, which the bearings probably wouldn’t bear.[/quote]
It would be exponential in scenario 2 as the plane would constantly be accelerating.
How fast does a plane taking off in the opposite direction of the rotation of the planet have to go?
Why is that any different than a treadmill?
[quote]SkyzykS wrote:
How fast does a plane taking off in the opposite direction of the rotation of the planet have to go?
Why is that any different than a treadmill?
[/quote]
LOL! The plane would fall off the edge of the treadmill. The question is flawed in so many ways. Thanks for revealing another one.
If you stop the treadmill, will the plane suddenly thrust forward or be thrown backwards?
[quote]SkyzykS wrote:
If you stop the treadmill, will the plane suddenly thrust forward or be thrown backwards?
[/quote]
Lol, no clue.
I can’t believe you guys are seriously discussing this.
Yes.
Geez man, I don’t know. I’m not a rocket scientist.
What if Superman rotated the earth in the opposite direction of the treadmill while a giant fan blew on the front of the plane on a giant variable treadmill set to match double the forward speed of the airplane?
[quote]Donut62 wrote:
What if Superman rotated the earth in the opposite direction of the treadmill while a giant fan blew on the front of the plane on a giant variable treadmill set to match double the forward speed of the airplane?[/quote]
Yes. It works.
I don’t care what anyone says. It works.
[quote]SkyzykS wrote:
How fast does a plane taking off in the opposite direction of the rotation of the planet have to go?
Why is that any different than a treadmill?
[/quote]
Because the atmosphere is also “rotating”. So within the confines of the earth it doesn’t really matter. I guess.
[quote]JoeG254 wrote:
Hahahahaha, on another forum I freuent there was a humongous 57 page thread on this that lasted almost an entire year.[/quote]
It wasn’t a website for a drummer for a well known prog band was it? If not, I know of another one.
Physics needs to be required in school.
[quote]beebuddy wrote:
In that case let’s give the plane frictionless bearings, in which case it would take off because the ground beneath might as well be “aether.”[/quote]
Doesn’t it have to move fast enough relative to the air to generate lift?
Wait, how many double-seater porkers are on board? What’s are the stewardessesses wearing? Pants or skirts??
Details dammit, I need details!
[quote]nephorm wrote:
beebuddy wrote:
In that case let’s give the plane frictionless bearings, in which case it would take off because the ground beneath might as well be “aether.”
Doesn’t it have to move fast enough relative to the air to generate lift? [/quote]
Sure but with perfect bearings the action of the treadmill wouldn’t have any affect have on the plane, so the jet/prop thrust would pump the plane forward (relative to the atmosphere) even if the treadmill were blasting away at light speed.
[quote]hungry4more wrote:
I can’t believe you guys are seriously discussing this. [/quote]
This is epic internet business. Serious business.
[quote]beebuddy wrote:
nephorm wrote:
beebuddy wrote:
In that case let’s give the plane frictionless bearings, in which case it would take off because the ground beneath might as well be “aether.”
Doesn’t it have to move fast enough relative to the air to generate lift?
Sure but with perfect bearings the action of the treadmill wouldn’t have any affect have on the plane, so the jet/prop thrust would pump the plane forward (relative to the atmosphere) even if the treadmill were blasting away at light speed.[/quote]
If you leave a skateboard on a treadmill will it be stationary or will it fly backwards?