That plane/conveyor problem - filmed solution
Discussion
paulie-mafia said:
That skateboard / fan set-up bears no relation to the plane scenario. The skateboard doesn't have wings or anything to give it lift and the guy tugging the paper from underneath it is doing so in an inacurate manner that doesn't exactly match the opposing force of the fan / skateboard as it needs to.
Can't believe I'm doing this, but hey ho -
The contention in the original pointless threads wasn't really about lift. Lift is generated by movement of air under and over the wings, and movement of air is generated by forward travel. People simply couldn't get their head around the fact that he plane would move forward in the first place, which is where the trouble arose.
In proving that it does actually move forward, this video is a very good demonstration of the physics involved. Once it moves forward, then you have lift and you have take off.
The fact that it isn't a real speed-matching conveyor belt doesn't matter - the guy could have pulled the piece of paper faster than the speed the wheels where turning but the skateboard would still move forward.
Sorry guys. Had to.
Edited by -DeaDLocK- on Monday 11th December 15:00
-DeaDLocK- said:
paulie-mafia said:
That skateboard / fan set-up bears no relation to the plane scenario. The skateboard doesn't have wings or anything to give it lift and the guy tugging the paper from underneath it is doing so in an inacurate manner that doesn't exactly match the opposing force of the fan / skateboard as it needs to.
Can't believe I'm doing this, but hey ho -
The contention in the original pointless threads wasn't really about lift. Lift is generated by movement of air under and over the wings, and movement of air is generated by forward travel. People simply could get their head around the fact that he plane would move forward in the first place, which is where the trouble arose.
In proving that it does actually move forward, this video is a very good demonstration of the physics involved. Once it moves forward, then you have lift and you have take off.
The fact that it isn't a real speed-matching conveyor belt doesn't matter - the guy could have pulled the piece of paper faster than the speed the wheels where turning but the skateboard would still move forward.
Sorry guys. Had to.
Fine work Deadlock. Now someone quickly lock it before the flatearth society come back and start posting....
But I thought the conveyor moved to keep it still? Or is that impossible and it would always move forward, no matter what - i.e. even if the wheels had to spin at 90 ga-billion-jillion RPM and the friction in the bearings stopped them doing so but the conveyor could move?
:P sorry, I just can't resist!
:P sorry, I just can't resist!
MTv Dave said:
But I thought the conveyor moved to keep it still? Or is that impossible and it would always move forward, no matter what - i.e. even if the wheels had to spin at 90 ga-billion-jillion RPM and the friction in the bearings stopped them doing so but the conveyor could move?
:P sorry, I just can't resist!
:P sorry, I just can't resist!
Ask yourself, Why does a plane on a normal airstrip move forward????
Is it because the wheels turn and move the plane OR is it because the plane engines thrust against the air PUSH the plane forward?????
If you think a plane moves cos the wheels are made to turn then ......
Because of the thrust, but there are limits on the speed the wheels can rotate at.
If the conveyor has some magic field that can keep the plane still then how does the plane move forward? I thought the whole premise for this was that the plane was stationary because of this magic?
ETA - I'm just seeing the wheels as a way to reduce the friction between the plane and the ground when the velocity is too low for the plane to create ehough lift to counter the force gravity. If they weren't there the plane couldn't move very easily.
I thought this conveyor belt was acting like magic bean juice derived glue that could stick the plane in one latitude/longiture location until it could create ehough lift to take off.
Or is it just a moving floor?
If the conveyor has some magic field that can keep the plane still then how does the plane move forward? I thought the whole premise for this was that the plane was stationary because of this magic?
ETA - I'm just seeing the wheels as a way to reduce the friction between the plane and the ground when the velocity is too low for the plane to create ehough lift to counter the force gravity. If they weren't there the plane couldn't move very easily.
I thought this conveyor belt was acting like magic bean juice derived glue that could stick the plane in one latitude/longiture location until it could create ehough lift to take off.
Or is it just a moving floor?
Edited by MTv Dave on Monday 11th December 15:51
MTv Dave said:
Because of the thrust, but there are limits on the speed the wheels can rotate at.
If the conveyor has some magic field that can keep the plane still then how does the plane move forward? I thought the whole premise for this was that the plane was stationary because of this magic?
If the conveyor has some magic field that can keep the plane still then how does the plane move forward? I thought the whole premise for this was that the plane was stationary because of this magic?
magic. Yes magic. pass me the gun, ive reached the end.
Edited by swilly on Monday 11th December 15:49
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