But it won't because the treadmill is only driving the wheels, if the wheels are capable of spinning at 500k mph they'll have such low friction with the plane that the plane won't be moved at all by them being spun.
Earth spinning
- Thread starter mollymoo
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So you are saying that if you stood on a treadmill wearing roller skates it would be just as easy to hold yourself on if it was going 500,000mph as it would be at 10mph?
If the wheels on the skates had such good bearings that they were able to accellerate to that speed, then yes there would be little difference.
Now you are just being awkward. The treadmill is fixed to the ground, the belt is moving backwards at 500,000mph. At this speed a large force will be emparted onto the plane, this forces increases both with the weight of the aircraft and the speed of the belt.
The wheels on the skates have normal bearings and I think there would be a massive difference. It's not about bearing friction (which is constant) it's about some rotational energy being transfered through the axle as a linear force. At high speeds this force can be significant. Assuming limitless speeds a speed could be reached so that this force would balance the force of a jet engine.
exactly
youd need the tiniest amount of thrust to negate the friction in the bearings
anyway i dont know why were arguing because this has been proved again and again by various people , scientists , engineers and also proven on mythbusters
where this 'large force' coming from ? there isnt one !!!!
just go hold a toy car or rollerskate on a treadmill and see how it needs hardly any 'thrust' at all to stop it moving backwards
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If they did then they couldn't be accellerated to that speed. If you're going to tweak one bit of the problem, it will change other bits to balance it out, and the end result is always going to be that the plane can fly
well for a start why 500 000mph . a plane surely only needs to do a few hundred to take off.
but assuming the bearings can cope with the speeds used (in the case of a plane they CAN, just wont last as long as normal) then yes it would be just as easy . go try it. weight and speed have no effect because thats what a bearing bloomin does
And now crank that treadmill up to 500,00mph and push down on the toy car to simulate the weight of a plane. Still think it will require the same effort to hold still?
And any that it does need will be as a result of the wheels not having frictionless axles, or uneven friction with the surface, it's more likely for it to suddenly have more force on one wheel than another which would cause it to jerk than it is to struggle to remain still.
Thats what a perfect bearing does. We are not talking about perfect bearings.
assuming the bearings are spec'd for those speeds ( which irl they cant be because its a silly speed btw) then yes because weight and speed dont even come into it
Then we're not talking about 500,000 mph treadmills either. If you want your wheels on a plane to spin freely at 500,000 mph they need to be near perfect bearings.
the ones in planes are perfect enough to spin at twice the speed they normally spin at though and thats all we need. im not saying there will be no friction in the bearings becaus there will be. but it wont be enough to stop the plane being thrusted forwards by the jets or props
Check back on my posts and you will see that I stated that the wheels would melt/explode before reaching this stage. Which goes back to my example of a 757 with its parking brake on, it ain't budging. As stated earlier I agree that with a lighter aircraft with more powerful engines it would take off due to being able to travel forwards without wheels. But in the case of an average airliner it ain't moving.
It would be if the treadmill went fast enough.
You want your treadmill to turn at 500,000mph it's going to need perfect parts too
Therefore if you're assuming the treadmill can go to any speed due to it's incredible manufacturing the plane must also be held to the same standard otherwise it's not comparable
as such the tread mill must be limited by physical limits (which would be far lower than the planes wheels) or both must be unlimited.
You'd need them for your super treadmill
If you can invent a technology to accelerate a treadmill to 50000000mph for the purpose of this question then I want my plane to share the same technology and therefore it takes off.