NEWS FLASH: The SuperMax/zTroll has set a new land speed record ... in his garage ... on a treadmill (sitting perfectly still of course). He argues that he isn't going to claim the record for himself, or even his car, but rather just for his tires. JB
force/lbs of resistance, as provided by the rolling resistance of the tires, etc. Shouldn't this be zero, since the Q assumes that the belt can spin at whatever speed necessary, therefore the other side needs to state that the wheels will spin freely? Or do you see it another way?
Haroki: X + (conveyor belt speed*y) = (wheel speed * y) + (100,000 lb thrust - 40,000 lb aerodynamic drag) Me: What is "y" standing in for? Haroki: force/lbs of resistance, as provided by the rolling resistance of the tires, etc. There must be one value for "y" in any single equation. I don't think the rolling resistance of the treadmill itself "(conveyor belt speed*y)" will be the same as the rolling resistance of the wheels "(wheel speed * y)". However, if you're right and I'm wrong, you should be able to show the work solving the equation for "y". Can you? JB
LOL There's a reason that circular actions are measured in *revolutions*, while linear actions are measured in *distance*. Hint: One actually moves you somewhere -- can you figure out which one? JB
The only resistance that the belt can provide is a source of rolling resistance, normally provided by the asphalt. There is no aerodynamic restance provided, right? The only interaction between the belt and the tires will be that rolling resistance. Or do you see something else? What I'm attempting to do is explain that since the belt has no limitations, then neither should the tires, and since the interaction between the 2 will be rolling resistance, then it's logical to make that assumption. Cuz if we start discussing the situation whereby the belt has no limitations, but the plane does, then it becomes a silly one. Thereby, by that assumption, y=0.
You and I certainly agree that compared to the engines pulling the plane, the resistance of the wheels will be minimal. It's not actually zero, but you are probably just saying "effectively zero", and not "actually zero". JB
Correct. One COULD figure out rolling resistance, but what would be the point? Cuz you'd then need to figure out the realities of a belt, etc.... The point of the Q, as I read it, is could a belt provide enough resistance , through enacting a ridiculously high rolling resistance, to prevent a plane from taking off. The tires would blow if the belt was robust enough. I think of the experiment, in the real world, like this: 1-Put a plane on a belt with a motion sensor attached. 2-Put a stationary sensor next to it, with a feedback loop that would control the belt speed. 3- as the pilot advances the throttle, the 100,000 lbs of thrust wouldn't go to accelerating the mass of the plane initially, but accelerating the spinning mass of the tires. 4-100,000 lbs of thrust would result in the tires being spun up to 1,000mph in an instant, assuming the belt could keep up. 5-the tires blow, end of plane... So, if you tried to include reality into the equation, where's the cutoff? An arbitrary cutoff would affect the outcome, depending on where you put it. Therefore, it's better to eliminate it.
This is too funny. THAT is why I continued reading! The patient teacher can't help himself/herself sometimes. lol