Airplane on a Conveyor Belt...

[sluggish]

I haven't redefined anything.  I'm sticking to my story.  You claim that resistance to rotational inertia doesn't exist, that the belt is moving the same direction as the plane (and that it doesn't make any difference which way the belt is moving...)

I'm starting to think that you are intentionally being silly for your own amusement.

[AKIron]

Originally posted by 2bighorn
For Christ sake, read it again and pay attention to wheel weight.
I did not invent the story. Eskimo is responsible for all the parameters, he defined them. He couldn't give satisfactory answer on his own question.

Whenever you guys get the answer, you redefine the question. Suddenly we got air conditioners, what's next? Ann Coulter in the trunk?

Only trying to help you understand the forces involved. Wheels spinning under the plane have more energy than wheels in the back seat. Same as the A/C pump under the cowling. All have the same mass but the pump spinning stole more of that engine power, same as did those more massive spinning wheels.

Not just at you 2bighorn but I try to avoid ridiculing others when there's a possbility I don't understand something. Less foot in the mouth when the light comes on. Just saying.

[john9001]

Originally posted by sluggish
I haven't redefined anything.  I'm sticking to my story.  You claim that resistance to rotational inertia doesn't exist, that the belt is moving the same direction as the plane (and that it doesn't make any difference which way the belt is moving...)

I'm starting to think that you are intentionally being silly for your own amusement.

this whole argument is hypothetical and silly.

and the plane will fly, and if you turn the whole thing upside down the plane will fall off the belt no matter how fast the belt runs.

why don't we discuss something important like how many angels can sit on the head of a pin?

[AKIron]

Originally posted by john9001
sorry, but my plane doesn't have wheels, it has the same rollers and bearings as the belt, and they are capable of infinite speeds.

The wheels have only to accelerate their rate of spin fast enough to acquire enough energy to match the plane's power output. May not be an impossible task to create this situation.

[2bighorn]

Originally posted by AKIron
Only trying to help you understand the forces involved.

So, you claim that Eskimo is right and there will be difference in take off run due to different wheel mass (which you compensated for with the ballast, btw) and that applying the law of physics is not enough?

You are trying to help me understand, yet you can't write down simple formula,  which will disapprove second law of motion which I used to disapprove Eskimo's claim?

Anyways, I'm thankful you're trying to educate me, but please, try it the way I CAN understand why physic's laws do not apply in this particular case.

[hitech]

Chairboy: The one I calculated last year.





Did some simple estimations of my RV on the conveyor.

Some how I knew I was going to have to do a drawing.

Also here is the reference page.

http://hyperphysics.phy-astr.gsu.edu/hbase/mi.html

HiTech

[john9001]

it is the energy from the belt that is spinning the wheels , not the thrust from the plane.

wheels are designed to roll, that is their job, all the wheels do is keep the fuselage from dragging on the ground.

the belt can not stop the plane, all the belt can do is spin the wheels.

[hitech]

john9001: with out an axle, and a force on that axle. A wheel does not roll on a conveyor. That force is from the engine.

Unless of course the conveyor is accelerating , them there also a  force from the mass of the wheel being accelerated that will start the wheel rotating but it will also be moving in the direction of the conveyor.


HiTech

[sluggish]

So what does all that mean HiTech?  Does the dam thing fly or not??

My theory is that with enough constant exceleration moment of inertia will over come the thrust of the plane and t5he plane won't fly.  Unless the wheels have zero mass in which case moment of inertia doesn't exist and the plane will fly.

[balance1]

oh god......we've even got the big man in on this one, this cant be good

[hitech]

Originally posted by sluggish
So what does all that mean HiTech?  Does the dam thing fly or not??

My theory is that with enough constant exceleration moment of inertia will over come the thrust of the plane and t5he plane won't fly.  Unless the wheels have zero mass in which case moment of inertia doesn't exist and the plane will fly.

Sluggish: If you continually accelerate the conveyor at 910 Feet per second per second. Then the plane will not move.

[2bighorn]

Originally posted by hitech
Unless of course the conveyor is accelerating , them there also a  force from the mass of the wheel being accelerated that will start the wheel rotating but it will also be moving in the direction of the conveyor.

...If you continually accelerate the conveyor at 910 Feet per second per second. Then the plane will not move.

We stopped short in last thread because we couldn't agree on which direction the wheel/belt friction torque should point after we moved it tangentially to the pivot point of the opposing vector, and for how much we have to adjust the magnitude of radial component of torque's pseudo vector, although we came pretty close.

[sluggish]

Originally posted by hitech
Sluggish: If you continually accelerate the conveyor at 910 Feet per second per second. Then the plane will not move.

Thank you sir.  I consider this case closed.













I WIN!!

[john9001]

Originally posted by hitech
Sluggish: If you continually accelerate the conveyor at 910 Feet per second per second. Then the plane will not move.

the tire will spin, the plane will move.

[Chairboy]

The problem w/ the 910^2 answer is that it implicitly seems to assume that the power is being transferred through the tires.  The diagram doesn't explain how this overcomes the u*N friction co-efficient math that shows the bearing friction as linear and constant.  A wheel spinning at 5 rpm induces as much bearing drag (the relevant figure here) as one at 100rpm.