Dan, you made a mistake in writing off option C.
As in my experiment above, you can see that the wheels and runway are coupled, i.e. as long as there is no skidding the linear velocities of the wheel diameter and runway surface must always be identical.
As in my experiment above, you can see that the wheels and runway are coupled, i.e. as long as there is no skidding the linear velocities of the wheel diameter and runway surface must always be identical.
I agree that in reality the plane would take off and so as I stated in my previous post the question itself is flawed.
C is flawed because according to the original question the wheel speed must match the belt speed in the opposite direction.
Al which direction were you pulling the paper??? (relative to the motion of the wheel in a linear direction towards the edge of the table).
Tony.
Tony.
This is fun!
And I don't think we've ever had so many mods involved in one thread before, (SY, Dave, J-P, where are you? ). 🙂
And I don't think we've ever had so many mods involved in one thread before, (SY, Dave, J-P, where are you? ). 🙂
Ok if you put it that way. We have to assume the following.
That Newton's laws of motion are true and apply to our situation.
That the laws of aerodynamics apply.
And that the experiment is not taking place in a vacuum
That the earth's gravity exists.
ahhh and Al you have just stated one of the different interpretations 😉 ie the linear velocity of the wheel as opposed to the angular velocity, these two interpretations make a BIG difference 😀
Tony.
Tony.
wintermute said:
I tried both ways, both in the direction of the force and against it. No difference, apart from a slight slowing when pulling the paper against the direction of the force, probably due to my "less than aerospace quality" bearings! 🙂
wintermute said:
OK, to clarify the linear velocity of the diameter of the wheel, not the linear velocity of the axis of the wheel.
Better? 🙂
pinkmouse said:
OK I would have thought that pulling the peice of paper toward the edge of the table (ie the direction the wheel was moving in) would be the one that slightly slowed it down.... go figure unless I've just misinterpreted your reply
Tony.
pinkmouse said:
now you have gone and confused me Al 😉 and I'm starting to wonder whether my previous post actually made sense
in (one of) my interpretations I felt that the linear speed of the wheel (taken at the axis) could easily match the linear speed the belt was moving in the opposite direction.
however the speed that the edge of the wheel is going can't possibly be equal to the speed the belt is moving because they aren't the same diameter..... however the relative speed of the belt can MATCH the speed of the wheels rotational speed due to the gearing effect the linear speed of the belt will be quite different..... oh nuts I've confused myself....
Tony.
Wintermute, old bean.....
Now I see the issue, it does not state what the 'speed' is linked to, sorry for only seeing the rotational speed thing...
This now sends me back to my first thought about blowing tyres although I still see the inferrence as being surface speed, i.e. the speed of the surface of the tyre matche by the surface speed of the belt.
You are right and therefore no real conclusion can be made it's either blow out and crash or lift off and byebye
Now I see the issue, it does not state what the 'speed' is linked to, sorry for only seeing the rotational speed thing...
This now sends me back to my first thought about blowing tyres although I still see the inferrence as being surface speed, i.e. the speed of the surface of the tyre matche by the surface speed of the belt.
You are right and therefore no real conclusion can be made it's either blow out and crash or lift off and byebye
Another assumptions must be that the conveyor belt is as long as the normal takeoff and landing track should be. Otherwise the airoplane won't be able to build up enough speed to be able to take off.
ahhhh surface speed of the belt matching the surface speed of the tire, that's a much better way of putting it than what I was trying to say thanks lost cause 🙂
Tony.
Tony.
Other assumptions..the motors work, the aeroplane has fuel, the fuel pumps work, the pilot wants to take off..the pilot knows how to take off. .....bla..bla...bla.
wintermute said:
I'll tell you what though, just imagine the speed of wheel rotation if it is matched by the rotational speed of the belt? The tyres would probably evaporate after about 2 seconds! It would give you an expodential increase in RPM that would......blimey!
Sorry bas, just has been drummed into me about reading the question properly 😉 and ambiguous questions are a real pita.
Tony.
Tony.
Then again..if the tires will turn so fast that they will explode..the airoplane won't take off.
So we have to assume that the tires can turn at infinite speed and the bearings won't heat up enough to seize. (which is not possible) Therefore both camps are right depending on the assumptions they make.
So we have to assume that the tires can turn at infinite speed and the bearings won't heat up enough to seize. (which is not possible) Therefore both camps are right depending on the assumptions they make.
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