Final answer to the airplane on a long treadmill problem ...

[ATK_Designs]

No, it is not the same:

The wheels on my car are powered by my engine... what are the wheels powered by on a plane?

Another example: Let's say that my car is on a dyno in neutral...and I have a jet engine attached to it. I crank up the engine, what happens to my car on the dyno?

Dude, the wheels of the plane are freespining. I was sampled backward. If you must match the plane/treadmill (motorized) example, you must attach the jet engine TO the dyno.

In that case you'll move the whole Dyno station backward. But in this subject, the car (treadmill) must have matching negative speed as the dyno wheels are putting.

Interlude, you do realize that the statement "The treadmill does output HP and TQ, in negative direction" is true, but that it is ONLY doing this on free-spinning wheels, right?

I was talking about the motorized treadmill.

So in this subject, the treadmill is free spinning and NOT motorized??:confused:

If so, you're 100% correct. It's the same as those air plane on the water. It WILL LIFT OFF.

[Ruiner]

I was talking about the motorized treadmill.

So in this subject, the treadmill is free spinning and NOT motorized??:confused:

If so, you're 100% correct. It's the same as those air plane on the water. It WILL LIFT OFF.

No, the treadmill is motorized, but the wheels of the plane are free spinning. The treadmill has torque, but it ONLY applies it to wheels that are free spinning.

Your dyno question was wrong in a sense. The wheels on the car would need to be free spinning (in neutral) as well. Will the dyno work and apply torque to the car if the car is in neutral? Nope. Just like the treadmill will not apply torque to the plane if the wheels are free spinning.

[ATK_Designs]

No, the treadmill is motorized, but the wheels of the plane are free spinning. The treadmill has torque, but it ONLY applies it to wheels that are free spinning.

Your dyno question was wrong in a sense. The wheels on the car would need to be free spinning (in neutral) as well. Will the dyno work and apply torque to the car if the car is in neutral? Nope. Just like the treadmill will not apply torque to the plane if the wheels are free spinning.

Oh okay,

but I was NOT talking in the sense that your car is in neutral + jet engine, no, not that.

I was talking about the plane's wheels = the same as the dyno's rollers.
And the treadmill = the car itself.

Lift up or not is based on air pressure. if there aren't any, plane will not lift off. Also, the treadmill will adjusting its negative velocity accordingly to the plane's.

Using the car vs dyno was a bad example. It was only to show you that the treadmill does output torque and HP in negative X direction to cancel out the free rolling velocity in positive X direction.

[Ruiner]

Oh okay,

but I was NOT talking in the sense that your car is in neutral + jet engine, no, not that.

I was talking about the plane's wheels = the same as the dyno's rollers.
And the treadmill = the car itself.

Lift up or not is based on air pressure. if there aren't any, plane will not lift off. Also, the treadmill will adjusting its negative velocity accordingly to the plane's.

Using the car vs dyno was a bad example. It was only to show you that the treadmill does output torque and HP in negative X direction to cancel out the free rolling velocity in positive X direction.

HOW is it cancelling the forward velocity, though?

Answer these questions for me:
- The treadmill is only spinning the wheels of the plane, yes?
- The wheels of the plane are free rolling, yes?
- Can spinning free rolling wheels cancel out the forward velocity of the plane?

I want you to think about that last question really hard... It actually makes the wheels spin faster. Look below: