# Physics Question
**URL:** https://forums.speedlife.net/t/physics-question/102635
**Category:** SON240sx Automotive
**Created:** [December 22, 2006, 7:23am UTC](https://forums.speedlife.net/t/physics-question/102635 "2006-12-22T07:23:38Z")
**Posts on this page:** 20
**Page:** 6
### Author:  [@louis110](https://forums.speedlife.net/u/louis110)
#### Post date: [December 22, 2006, 6:10pm UTC](https://forums.speedlife.net/t/physics-question/102635/101 "2006-12-22T18:10:59Z")
please tell me what i said that was wrong. im not being defensive here im trying to keep an open mind
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### Author:  [@Sasha\_SG](https://forums.speedlife.net/u/Sasha_SG)
#### Post date: [December 22, 2006, 6:24pm UTC](https://forums.speedlife.net/t/physics-question/102635/102 "2006-12-22T18:24:37Z")
its hard to point out exactly where it is wrong, it just doesnt make sense. a lot of the stuff you say is very difficult to read and when broken down (without all the big boy physics words) it doesnt make sense. let me give you a few examples:
i failed to observe one very obvious property of the situation. the belt and the motion of the plane spin the wheels in the same direction!
the belt AND the motion of the plane? i think only the belt is spinning the wheels. this sentance would make more sense if it said something like this:
the belt spins the planes wheels in the same direction.
but then it still doenst make sense. same direction as what? well i think what you meant to say is
the belt spins the plane’s wheels in a forward direction.
although it doesn’t matter at all, since you still haven’t proven that spinning the planes wheels forward OR backwards has any effect what so ever on the planes actual movement (which is based entirely on the fact that huge amounts of gasoline are being burnt and forced out of nozzles at ridiculious velocities slamming the huge peice of metal forward no matter what the ground tries to do)
“so the tangential velocity of the wheels is actually doubled instead of cancelling out.”
this sounds like something battle auto salon would say. why did you even use the word tangential? how does speed cancel out?
anyways, i think you get my point
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### Author:  [@Solarian](https://forums.speedlife.net/u/Solarian)
#### Post date: [December 22, 2006, 6:35pm UTC](https://forums.speedlife.net/t/physics-question/102635/103 "2006-12-22T18:35:38Z")
> [@Callout!](https://forums.speedlife.net/t/callout/10653/140):
>
> ok so i must admit defeat on this one…after lying down in my bed and playing with my toy planes, i failed to observe one very obvious property of the situation. the belt and the motion of the plane spin the wheels in the same direction!
> -Yup.
> so the tangential velocity of the wheels is actually doubled instead of cancelling out.
> -Yup.
> this is of course based on the assumption the system is TOTALLY frictionless and all rotational inertia is overcome.
> -Yup.
> if the belt were moving in the same direction as the plane then my argument would be valid, but that’s just not the case here.
> -WRONG! The wheels would still freewheel, the plane would still do it’s own thing. You need to consider a frame of reference that is relative to the air, not to the belt. There will be an unbalanced force on the plane (thrust) propelling it forward. If there is no friction, then you’re off, if there is friction you slow down a tiny bit due to the friction, but you’re still off.
>
> i still stand by my theory in that the speed of the wheels is affected by the thrust created. though the systems are independent of each other, the motion caused by thrust along the ground can be also expressed by the tangential motion of the wheels.
> -True, but the wheel speed doesn’t matter. It’s completely irrelevant.
There are dashes before all of my replies
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### Author:  [@louis110](https://forums.speedlife.net/u/louis110)
#### Post date: [December 22, 2006, 6:55pm UTC](https://forums.speedlife.net/t/physics-question/102635/104 "2006-12-22T18:55:52Z")
ok to clarify my outlook on this:
you’re looking at the plane from its starboard side (plane is pointing to the right). ignoring the belt, when the plane moves forward the wheels spin clockwise. now lets say the belt spins but no thrust is being applied to the plane, the wheels still spin clockwise. if the plane moves forward at velocity X then wouldn’t the tangential velocity (in the left direction) of the wheels also equal X? Since the belt spins at the same velocity X, the motion of the belt is translated to the freespinning wheels hence the tangential velocity of the wheels is 2X.
“since you still haven’t proven that spinning the planes wheels forward OR backwards has any effect what so ever on the planes actual movement (which is based entirely on the fact that huge amounts of gasoline are being burnt and forced out of nozzles at ridiculious velocities slamming the huge peice of metal forward no matter what the ground tries to do)”
In order for the plane to move forward along the ground with the landing gear down, wouldnt the wheels need to spin (i.e. the motion of the plane is translated into the motion of the wheels)? if the contact between the wheels and the ground is frictionless then the wheels would just slide across the ground i guess.
im not saying the spinning of the wheels controls the motion of the plane, but the wheels allow the plane to roll along the ground with minimal losses dictated by the accleration caused by the thrust. if the plane had no landing gear (no belt either) the thrust would have to overcome the frictional forces of the ground [F(friction) = (friction coefficient of ground)(mass of plane)(acceleration due to gravity)] even then it would still have to have to provide enough thrust to allow the plane to accelerate to rotation speed (take off speed)
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### Author:  [@Lucidsnow](https://forums.speedlife.net/u/Lucidsnow)
#### Post date: [December 22, 2006, 8:08pm UTC](https://forums.speedlife.net/t/physics-question/102635/105 "2006-12-22T20:08:22Z")
the plane will take off with the engines on full throttle… haha so the plane will Fall off the belt… and crash and explodeeeeeeeeeee
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### Author:  [@TM1](https://forums.speedlife.net/u/TM1)
#### Post date: [December 22, 2006, 8:59pm UTC](https://forums.speedlife.net/t/physics-question/102635/106 "2006-12-22T20:59:58Z")
> [@where to get a grill(z)?](https://forums.speedlife.net/t/where-to-get-a-grill-z/10255/167):
>
> its hard to point out exactly where it is wrong, it just doesnt make sense. a lot of the stuff you say is very difficult to read and when broken down (without all the big boy physics words) it doesnt make sense. let me give you a few examples:
>
> i failed to observe one very obvious property of the situation. the belt and the motion of the plane spin the wheels in the same direction!
>
> the belt AND the motion of the plane? i think only the belt is spinning the wheels. this sentance would make more sense if it said something like this:
>
> the belt spins the planes wheels in the same direction.
>
> but then it still doenst make sense. same direction as what? well i think what you meant to say is
>
> the belt spins the plane’s wheels in a forward direction.
>
> although it doesn’t matter at all, since you still haven’t proven that spinning the planes wheels forward OR backwards has any effect what so ever on the planes actual movement (which is based entirely on the fact that huge amounts of gasoline are being burnt and forced out of nozzles at ridiculious velocities slamming the huge peice of metal forward no matter what the ground tries to do)
>
> “so the tangential velocity of the wheels is actually doubled instead of cancelling out.”
>
> this sounds like something battle auto salon would say. why did you even use the word tangential? how does speed cancel out?
>
> anyways, i think you get my point
Haha thank God you’re not a teacher/professor Sash…
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### Author:  [@Sasha\_SG](https://forums.speedlife.net/u/Sasha_SG)
#### Post date: [December 22, 2006, 9:37pm UTC](https://forums.speedlife.net/t/physics-question/102635/107 "2006-12-22T21:37:18Z")
anyyyyyyyyyywayyyyyyyyyyyyyyysss
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### Author:  [@alesserfate](https://forums.speedlife.net/u/alesserfate)
#### Post date: [December 22, 2006, 11:20pm UTC](https://forums.speedlife.net/t/physics-question/102635/108 "2006-12-22T23:20:08Z")
i owned myself now that i think about it… read post below
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### Author:  [@alesserfate](https://forums.speedlife.net/u/alesserfate)
#### Post date: [December 23, 2006, 12:20am UTC](https://forums.speedlife.net/t/physics-question/102635/109 "2006-12-23T00:20:48Z")
plane will take off, conveyor belt has nothing to do with planes speed unless plane puts on its brake (and does a forever ebrake stand lmao), plane gains its speed according to air mass and not conveyor belt, plane will take off because it will accelerate forward according to air mass/ground and since the wheels spin freely the conveyorbelt can go as fast as it can wont make any difference on the plane
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### Author:  [@Theo23](https://forums.speedlife.net/u/Theo23)
#### Post date: [December 23, 2006, 1:21am UTC](https://forums.speedlife.net/t/physics-question/102635/110 "2006-12-23T01:21:33Z")
^ right, the only difference the conveyor belt makes is that the wheels will be spinning at twice the planes speed, but in reverse. The faster the plane goes, the faster the wheels spin backwards… but, as stated before, that is irrelivant… cause the jet engines are propeling the plane, not the wheels…
It is a total trick question. I saw it form the beginning, but every time I went to reply, there were more and more replies to include… so I gave up. Now it is 4:20 AM and everyone is either sleeping or partaking… so this is my post… someone get me a glass of water…
haha how much frustration was created with this thread over the last day HAHA. suckers.
what do they say? It is better to keep your mouth closed and be thought a fool, than to open it and remove all doubt.
Theo
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### Author:  [@Uniac](https://forums.speedlife.net/u/Uniac)
#### Post date: [December 23, 2006, 6:07am UTC](https://forums.speedlife.net/t/physics-question/102635/111 "2006-12-23T06:07:56Z")
> [@SBC parts(heads, intake etc)](https://forums.speedlife.net/t/sbc-parts-heads-intake-etc/10479/4):
>
> i didnt read much of this thread… but i’ve seen this discussion before.
>
> Adam H is right, bar none.
>
> the wheels dont drive the plane, they are just there to make it roll, because they do not drive the plane the speed or even direction in which the wheels are spinning is indepentend of the plane’s speed even though in almost all circumstances they are equal under normal conditions.
>
> this is not a new question, i have seen it many times before and never in the last 6 months…lol…
>
> matt, im surprised you got this wrong, didnt you take part in the ZT thread on this last year?
>
> i saw like a 336543 page thread on a physics forum about this
Nope bing, never saw it, thinking about it now, i guess i can see where i missed the “boat”. Regardless it would never happed, but i guess thats why physics is the theoretical science.
anyways, apparently I stand corrected. AdamH you can go back to lurking now.
Sasha you can stop trying to make people look bad.
Bob…for once we agreed on something, and look what happens.
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### Author:  [@240sxfan](https://forums.speedlife.net/u/240sxfan)
#### Post date: [December 23, 2006, 7:46am UTC](https://forums.speedlife.net/t/physics-question/102635/112 "2006-12-23T07:46:46Z")
OK… i do not have a degree in anything but have been reading this post for a while and I started to agree with Louis and then Adam and now i agree with both…
here is how i see it in my tiny brain.
If there is no friction at all then the plane would definatley take off and fly, as everyone has agreed the thrust creates the forward motion not the wheels, they are simply just free rolling wheels. With zero friction the wheels could spin at whatever speed they wanted, the belt would match it and cancel them out, the plane would stand still as if it were floating in air and just levitating off the ground, add thrust from the engines and your off. Adam is right
now if there is friction it is a whole other story and calculations beyond what my brain can calculate. But in that case I would say that the plane would not take off and fly.
I’ll use the office chair example… if there is friction and the wheels can move at any possible speed without exploding or breaking, you put the chair on the conveyor belt then turn it on, the chair will move in the direction of the conveyor belt and fall off, you need something to hold/push it in place, friction/gravity/weight play a factor. Now hold the chair in place and turn on the conveyor, you need to use force to keep it in place because of friction so now if you push forward and the conveyor matches the speed of the wheels, you need even more pushing force just to keep it in place because of the friction. To me, if friction is a factor then the ammount of thrust from the planes engine would have to be greater then the ammount of force/drag created by friction for the plane to move forward and I see it as standing still in the same spot with the thrust at full blast.
To me the answer can go both ways depending if there is friction or not.
I go relax my stressed brain now…
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### Author:  [@TM1](https://forums.speedlife.net/u/TM1)
#### Post date: [December 23, 2006, 8:58am UTC](https://forums.speedlife.net/t/physics-question/102635/113 "2006-12-23T08:58:14Z")
> [@Official Thread: Snakes on a Plane](https://forums.speedlife.net/t/official-thread-snakes-on-a-plane/10495/7):
>
> Nope bing, never saw it, thinking about it now, i can see where i missed the “boat”. I Posed the question to an uncle who designed the DC10 wing span, he said no, then hesitated, countered and explained. Regardless it would never happed, but i guess thats why physics is the theoretical science.
>
> anyways, I stand corrected. AdamH you can go back to lurking now.
> Sasha you can stop trying to make people look bad.
> Bob…for once we agreed on something, and look what happens.
Haha, the irony…
No worries, I’m sure we agree on more then a few things…
One being that Sasha can stop trying to make people feel bad…
No worries 🙂
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### Author:  [@Sasha\_SG](https://forums.speedlife.net/u/Sasha_SG)
#### Post date: [December 23, 2006, 9:47am UTC](https://forums.speedlife.net/t/physics-question/102635/114 "2006-12-23T09:47:58Z")
i love you all so much
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### Author:  [@Solarian](https://forums.speedlife.net/u/Solarian)
#### Post date: [December 23, 2006, 9:52am UTC](https://forums.speedlife.net/t/physics-question/102635/115 "2006-12-23T09:52:41Z")
> [@$FREE$ factory service manuals!! :D](https://forums.speedlife.net/t/free-factory-service-manuals-d/10230/14):
>
> now if there is friction it is a whole other story and calculations beyond what my brain can calculate. But in that case I would say that the plane would not take off and fly.
> I’ll use the office chair example… if there is friction and the wheels can move at any possible speed without exploding or breaking, you put the chair on the conveyor belt then turn it on, the chair will move in the direction of the conveyor belt and fall off, you need something to hold/push it in place, friction/gravity/weight play a factor. Now hold the chair in place and turn on the conveyor, you need to use force to keep it in place because of friction so now if you push forward and the conveyor matches the speed of the wheels, you need even more pushing force just to keep it in place because of the friction. To me, if friction is a factor then the ammount of thrust from the planes engine would have to be greater then the ammount of force/drag created by friction for the plane to move forward and I see it as standing still in the same spot with the thrust at full blast.
>
> To me the answer can go both ways depending if there is friction or not.
> I go relax my stressed brain now…
Planes make 80-100 thousand-ish pounds of thrust. Friction isn’t gonna stop it, even if you’ve got the wheels locked with 4 corner Z brakes with hawk pads and hoosiers on the wheels. 😃
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### Author:  [@spd-dmn](https://forums.speedlife.net/u/spd-dmn)
#### Post date: [December 23, 2006, 11:21am UTC](https://forums.speedlife.net/t/physics-question/102635/116 "2006-12-23T11:21:34Z")
> [@Myspace \> 13 year old fucking hot blond teachers](https://forums.speedlife.net/t/myspace-13-year-old-fucking-hot-blond-teachers/10713/21):
>
> ^ right, the only difference the conveyor belt makes is that the wheels will be spinning at twice the planes speed, but in reverse. The faster the plane goes, the faster the wheels spin backwards… but, as stated before, that is irrelivant… cause the jet engines are propeling the plane, not the wheels…
>
> It is a total trick question. I saw it form the beginning, but every time I went to reply, there were more and more replies to include… so I gave up. Now it is 4:20 AM and everyone is either sleeping or partaking… so this is my post… someone get me a glass of water…
>
> haha how much frustration was created with this thread over the last day HAHA. suckers.
>
> what do they say? It is better to keep your mouth closed and be thought a fool, than to open it and remove all doubt.
>
> Theo
>
> ed, your gay
if the conveyor is moving backward, the wheels are moving forward 🙂
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### Author:  [@Cal](https://forums.speedlife.net/u/Cal)
#### Post date: [December 23, 2006, 12:51pm UTC](https://forums.speedlife.net/t/physics-question/102635/117 "2006-12-23T12:51:20Z")
If a plane is at cruising speed and altitude, and it is traveling 1000kms against the rotation of the Earth will it get to its destination faster than a plane that is traveling the same distance at the same altitude and same speed with the rotation of the Earth?
Considering there are no adverse effects such as wind speed/direction or atmospheric pressures etc.
I think this scenario can be applied to the coneyor question.
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### Author:  [@DJPyro](https://forums.speedlife.net/u/DJPyro)
#### Post date: [December 23, 2006, 4:26pm UTC](https://forums.speedlife.net/t/physics-question/102635/118 "2006-12-23T16:26:21Z")
> [@Went out for a bag of milk.....](https://forums.speedlife.net/t/went-out-for-a-bag-of-milk/10585/53):
>
> If a plane is at cruising speed and altitude, and it is traveling 1000kms against the rotation of the Earth will it get to its destination faster than a plane that is traveling the same distance at the same altitude and same speed with the rotation of the Earth?
>
> Considering there are no adverse effects such as wind speed/direction or atmospheric pressures etc.
>
> I think this scenario can be applied to the coneyor question.
Actually, it will get to its destination faster.
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### Author:  [@Theo23](https://forums.speedlife.net/u/Theo23)
#### Post date: [December 23, 2006, 4:28pm UTC](https://forums.speedlife.net/t/physics-question/102635/119 "2006-12-23T16:28:32Z")
> [@Scientists Find Missing Link in Human Evolution...](https://forums.speedlife.net/t/scientists-find-missing-link-in-human-evolution/10681/42):
>
> if the conveyor is moving backward, the wheels are moving forward 🙂
Yeah woops… twice the speed of the plane but in forward direction. :mad:
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### Author:  [@bing](https://forums.speedlife.net/u/bing)
#### Post date: [December 23, 2006, 4:30pm UTC](https://forums.speedlife.net/t/physics-question/102635/120 "2006-12-23T16:30:55Z")
jeez… can someone please start the conversation in this thread that i know you all want to have… heck, i have gotten at least 2 phone calls about it now and i’m doing my best to restrain myself.
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