Dude, you need to put down the peace pipe. The road doesn't match the speed of wheel.....that's why there is relative motion between both. Keep up the good work, that was hilarious.
think about it for a sec, as the wheel rotates on the road the contact patch is fixed in point to it. thus the road is travling at the same speed past the wheel.
If the wheel rotation didn't affect the takeoff and it only had to do with the wing being pushed forward, then just imagine the wheels are pinned so they can't turn. Will the plane take off? No, the plane won't be able to overcome the static friction of the tire against the runway. Ever try to take off with the wheels chocked? You can blow air and burn gas at full power and you won't take off. Wheel rotation does matter.
Dude, wheel speed refers to the center of the wheel. Not the unmoving contact patch. On a non-moving surface the wheel speed is the absolute speed.
speed of a wheel is RPM, the center or edge of a wheel travels at the same RPM. however the center vs edge will travel different distances in that same revolution.
I dunno if you guys saying it wont take off are kidding???? You guys are assuming the plane would say in place, but it wouldnt. All that would happen is that the speed of the plane *relative* to the moving runway would be would be faster than usual, but the plane would still go down the runway and take off. It is impossible for the moving runway to keep the plane in place, because the plane is not pushing against the runaway to generate its forward motion. Imagine you are 100 feet tall and strong like superman You are standing next to a car on a dyno. You bend down and squat next to it - the dyno starts and the car is idling at 5mph. You put your hand on the back of the car - the dyno operator matches the wheel speed exactly....can you push the car off the dyno? Absolutely you can, because the force you are applying cannot be negated by the dyno unless the car applied its brakes, and braking want in the original scenario.
I have come to what I believe is an impossibility in the scenario. Imagine in 2-dimentions, a toy car on a treadmill. The treadmill is moving from left to right, and you are holding the car still with your right hand. Using force (similar to jet engine thrust on the airplane), push the car to the left. Here's where it gets interesting. If the treadmill is matching wheel speed, the car can't go anywhere. But your hand will still move left. So what happens to the car? If the car moves to the left as well, then that means that wheel speed is overcoming treadmill speed. But the treadmill speed has no effect on the motion of your hand... I don't get it.
he doesn't explain it well either. that or the "it won't fly, rocky" dudes like me are just dunderheads (willing to accept!). i'm yet to see an argument that shows how the plane even moves forward. does it not have to move forward on it's wheels? the ground beneath it is being pulled away as fast as the wheels are spinning, the object remains stationary. yes, in the cartoon world i'm imagining Wile E Coyote pulling an endless rug out from underneath the Roadrunner, although he doesn't have the required appendages to fly anyway, he also doesn't move so even if he did he's not generating lift. in the end, the only velocity measurement is the relative velocity of the object vs the ground beneath. relative velocity to the earth - and therefore air - equals exactly zero.
yeah i saw that before and all it means is that he wasn't pulling the paper as quick as the wheels were turning, hence forward motion.
Its only an impossibility in that the treadmill/runway cannot keep up with wheel speed. It would almost instantly speed up to its maximum speed (or infinite speed) causing the bearings to cook and melt in the wheels of the airplane, causing it to slide along the runway, and get flung off the back like a fat chick falling on a treadmill
i agree with ash and Mr payne, the plane gaining any sort of forward motion just does no seem logical when i try to visualise this in my head
how???? the fan is pushing the skatebaord not the wheels. besides the paper is always matched to the speed of the wheel -always-
go grab a hotwheels car and a peice of paper. place the car on the paper and move the paper back and forth under the car. the speed of the paper matches the wheels whe nthe car is held in place by you. now move the car and move the paper, wheels and paper still move at the same speed, the car moves at varying rates of speed. this is why the plane can still fly.
it's rolling ON the wheels. if the coveyor MATCHED the speed of the wheels in the OPPOSITE direction the skateboard would remain stationary. how are people not getting this? what am *I* missing?? ok, what if he pulled the paper at 100mph, would it still roll forward? i can see the argument being posed about the thrust moving the object not the wheels being driven, but as far as i can tell if the object is moving forward AT ALL then the conveyor IS NOT moving at the same speed in the negative. does that make sense?
