# Physics Question **URL:** \ **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:** 5
**Author:** ![ADAMH](https://avatars.discourse-cdn.com/v4/letter/a/71e660/32.png) [@ADAMH](https://forums.speedlife.net/u/ADAMH)\ **Post date:** [December 22, 2006, 12:51pm UTC](https://forums.speedlife.net/t/physics-question/102635/81 "2006-12-22T12:51:18Z")
dont lock it… this is a good bicker debate…and fun… on the surface to some it seems very difficult…but the underlying issue is neat… ---
**Author:** ![Fobwall](https://avatars.discourse-cdn.com/v4/letter/f/7ea924/32.png) [@Fobwall](https://forums.speedlife.net/u/Fobwall)\ **Post date:** [December 22, 2006, 1:19pm UTC](https://forums.speedlife.net/t/physics-question/102635/82 "2006-12-22T13:19:23Z")
> [@WTB: 4x108 saab rims](https://forums.speedlife.net/t/wtb-4x108-saab-rims/10465/8): > > As i said before, if thrust was the sole issue to flight, we wouldnt have runways, we would just spin the turbine to full power and it would leap into the air. And the land speed cars would just fly off into space. lol that’s exactly what I was saying to someone. Launching an airplane into the air to make it fly would be like a spaceship or something, just let it get full thrust and drop it, and it should fly. Kinda like a missile i guess? ---
**Author:** ![Happy240sx](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/happy240sx/32/5515_2.png) [@Happy240sx](https://forums.speedlife.net/u/Happy240sx)\ **Post date:** [December 22, 2006, 2:11pm UTC](https://forums.speedlife.net/t/physics-question/102635/83 "2006-12-22T14:11:42Z")
\ Alright, based on this discussion…I’m gonna go the GTAA and recomend that instead of hundreds and hundreds of acres of runways, all we really need is a few busted old Dynojets…one for the front wheels and a couple for the sides. Booyeah - I’m a be rich! \ ---
**Author:** ![TM1](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/tm1/32/5517_2.png) [@TM1](https://forums.speedlife.net/u/TM1)\ **Post date:** [December 22, 2006, 2:31pm UTC](https://forums.speedlife.net/t/physics-question/102635/84 "2006-12-22T14:31:35Z")
> [@ADAMH"](#): > > dont lock it… > this is a good bicker debate…and fun… > > on the surface to some it seems very difficult…but the underlying issue is neat… Ok I stand corrected… The use of thrust to propel the plane is essentially using air to move the plane not anything to do with the running gear… I see what you mean now… My bad… ---
**Author:** ![TM1](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/tm1/32/5517_2.png) [@TM1](https://forums.speedlife.net/u/TM1)\ **Post date:** [December 22, 2006, 2:33pm UTC](https://forums.speedlife.net/t/physics-question/102635/85 "2006-12-22T14:33:16Z")
> [@Scientists Find Missing Link in Human Evolution...](https://forums.speedlife.net/t/scientists-find-missing-link-in-human-evolution/10681/31): > > Ok I stand corrected… > > The use of thrust to propel the plane is essentially using air to move the plane not anything to do with the running gear… > > I see what you mean now… > > My bad… The other thing to, is that if the wheels were truely frictionless, if you started that conveyor the plane wouldn’t move, because the frictionless wheels would simply spin in place… ---
**Author:** ![TM1](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/tm1/32/5517_2.png) [@TM1](https://forums.speedlife.net/u/TM1)\ **Post date:** [December 22, 2006, 2:35pm UTC](https://forums.speedlife.net/t/physics-question/102635/86 "2006-12-22T14:35:36Z")
> [@WTB: 4x108 saab rims](https://forums.speedlife.net/t/wtb-4x108-saab-rims/10465/10): > > The other thing to, is that if the wheels were truely frictionless, if you started that conveyor the plane wouldn’t move, because the frictionless wheels would simply spin in place… Geeze Adam why didn’t you come out and say so… 🙂 ---
**Author:** ![Osad](https://avatars.discourse-cdn.com/v4/letter/o/3ab097/32.png) [@Osad](https://forums.speedlife.net/u/Osad)\ **Post date:** [December 22, 2006, 2:45pm UTC](https://forums.speedlife.net/t/physics-question/102635/87 "2006-12-22T14:45:08Z")
I think you guys may have missed a fact that Cal brought up earlier i believe. If this conveyer belt is matching your speed, meaning the PLANE’s speed and not the WHEEL’s speed, this means that whatever amount of thrust you create will only sustain your position , if you decrease thrust, and the conveyer doesnt go down aswell, the plane WILL move backwards, even though the wheels are INDEPENDANT of the body, it can’t sustain its position on the belt. Therefore you would need to be able to somehow double your thrust by the time this conveyer reaches its limit and the plane has reached its limit, considering the conveyer has a limit (which the question doesnt state it does) just to create enough thrust to start moving as if the conveyer were not even there and you were starting from a standing still on regular ground. I think the question is a trick question, and does not provide enough parameters to possibly solve. ---
**Author:** ![Sasha\_SG](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/sasha_sg/32/5477_2.png) [@Sasha\_SG](https://forums.speedlife.net/u/Sasha_SG)\ **Post date:** [December 22, 2006, 2:50pm UTC](https://forums.speedlife.net/t/physics-question/102635/88 "2006-12-22T14:50:09Z")
ahhhh you people are looking at this all wrong!!! all that matters is the speed of the plane in relation to the air, it has NOTHING to do with the speed the wheels are moving or the conveyor. it might slightly hinder ground effects but the plane will still lift off the ground if the airspeed is high enough. if you want a tricky question you could ask a plane accelerates but there is a fan behind it blowing air forward at the exact same speed as the plane moves. in this case no matter what the speed of the plane if the airspeed is zero THEN the plane will not take off thats it game over p.s. i only read the first 5 posts ---
**Author:** ![Sasha\_SG](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/sasha_sg/32/5477_2.png) [@Sasha\_SG](https://forums.speedlife.net/u/Sasha_SG)\ **Post date:** [December 22, 2006, 2:54pm UTC](https://forums.speedlife.net/t/physics-question/102635/89 "2006-12-22T14:54:37Z")
i just read some other posts adam i feel bad for you dude hahahahha everyone was going against you when you were the only one that truely understood what was going on! hahaha ---
**Author:** ![NoSkillz](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/noskillz/32/5606_2.png) [@NoSkillz](https://forums.speedlife.net/u/NoSkillz)\ **Post date:** [December 22, 2006, 2:54pm UTC](https://forums.speedlife.net/t/physics-question/102635/90 "2006-12-22T14:54:53Z")
Relativity can provide a simple answer of understanding. The plane moves based on its relativity to air. Hence lift is created. Those that think the plane will fly when its on the tredmill are placing the tredmill as the relativity point which is incorrect when talking about air crafts and lift. When the plane is on the tredmill, the air being relative to the plane is not moving and therefor means no lift is generated. i hope this helps those that are confused ---
**Author:** ![Sasha\_SG](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/sasha_sg/32/5477_2.png) [@Sasha\_SG](https://forums.speedlife.net/u/Sasha_SG)\ **Post date:** [December 22, 2006, 3:09pm UTC](https://forums.speedlife.net/t/physics-question/102635/91 "2006-12-22T15:09:03Z")
HAHAHAHAHA i just read more dude this shit is so funny hahahhaha adam is liek the thrust nazi THRUST GOD DAMMIT WHY CANT YOU JUST UNDERSTAND THE THRUST!!! hahahaha you guys make me laugh ---
**Author:** ![TM1](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/tm1/32/5517_2.png) [@TM1](https://forums.speedlife.net/u/TM1)\ **Post date:** [December 22, 2006, 3:14pm UTC](https://forums.speedlife.net/t/physics-question/102635/92 "2006-12-22T15:14:11Z")
> [@Scientists Find Missing Link in Human Evolution...](https://forums.speedlife.net/t/scientists-find-missing-link-in-human-evolution/10681/33): > > HAHAHAHAHA i just read more > > dude this shit is so funny > hahahhaha > > adam is liek the thrust nazi > > THRUST GOD DAMMIT WHY CANT YOU JUST UNDERSTAND THE THRUST!!! > > hahahaha > > you guys make me laugh No one is perfect dude… relax… ---
**Author:** ![flyingchicken](https://avatars.discourse-cdn.com/v4/letter/f/ac91a4/32.png) [@flyingchicken](https://forums.speedlife.net/u/flyingchicken)\ **Post date:** [December 22, 2006, 3:59pm UTC](https://forums.speedlife.net/t/physics-question/102635/93 "2006-12-22T15:59:45Z")
while the plane is still standing at 0-FT. if theres a thrust meter in the cabin and it says 400mph, and the conveyer is saying 400mph, the plane will not go anywhere.it stays at 0-FT…if it was so easy to fly a plane with pure power/thrust, it wouldn’t have taken mankind a while to figure out how to get shit in the air. air has to lift the wings with speed to get shit to fly. ---
**Author:** ![Wiltzor](https://avatars.discourse-cdn.com/v4/letter/w/aeb1de/32.png) [@Wiltzor](https://forums.speedlife.net/u/Wiltzor)\ **Post date:** [December 22, 2006, 4:23pm UTC](https://forums.speedlife.net/t/physics-question/102635/94 "2006-12-22T16:23:35Z")
Tricky question Lith…got me for about 5 minutes… …until i realized that the wheels are totally independant of the turbines. Ze plane vill fly! ---
**Author:** ![bing](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/bing/32/7211_2.png) [@bing](https://forums.speedlife.net/u/bing)\ **Post date:** [December 22, 2006, 5:37pm UTC](https://forums.speedlife.net/t/physics-question/102635/95 "2006-12-22T17:37:07Z")
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 ---
**Author:** ![Lith](https://avatars.discourse-cdn.com/v4/letter/l/fbc32d/32.png) [@Lith](https://forums.speedlife.net/u/Lith)\ **Post date:** [December 22, 2006, 6:02pm UTC](https://forums.speedlife.net/t/physics-question/102635/96 "2006-12-22T18:02:20Z")
haha yeah Bing. That thread had 400+ pages on that physics forum. Crazy. ---
**Author:** ![louis110](https://avatars.discourse-cdn.com/v4/letter/l/ecae2f/32.png) [@louis110](https://forums.speedlife.net/u/louis110)\ **Post date:** [December 22, 2006, 6:02pm UTC](https://forums.speedlife.net/t/physics-question/102635/97 "2006-12-22T18:02:42Z")
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! so the tangential velocity of the wheels is actually doubled instead of cancelling out. this is of course based on the assumption the system is TOTALLY frictionless and all rotational inertia is overcome. 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. 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. so adam i must apologize to you for my ignorance and hostility, and i think i deserve a big ![http://son.my240.com/homerpicard.jpg](http://son.my240.com/homerpicard.jpg) ---
**Author:** ![Sasha\_SG](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/sasha_sg/32/5477_2.png) [@Sasha\_SG](https://forums.speedlife.net/u/Sasha_SG)\ **Post date:** [December 22, 2006, 6:04pm UTC](https://forums.speedlife.net/t/physics-question/102635/98 "2006-12-22T18:04:21Z")
> [@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! so the tangential velocity of the wheels is actually doubled instead of cancelling out. this is of course based on the assumption the system is TOTALLY frictionless and all rotational inertia is overcome. 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. > > 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. > > so adam i must apologize to you for my ignorance and hostility, and i think i deserve a big is what you type all a joke or do you actually believe this stuff? ---
**Author:** ![louis110](https://avatars.discourse-cdn.com/v4/letter/l/ecae2f/32.png) [@louis110](https://forums.speedlife.net/u/louis110)\ **Post date:** [December 22, 2006, 6:07pm UTC](https://forums.speedlife.net/t/physics-question/102635/99 "2006-12-22T18:07:22Z")
i certainly hope its not a joke ---
**Author:** ![Sasha\_SG](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/sasha_sg/32/5477_2.png) [@Sasha\_SG](https://forums.speedlife.net/u/Sasha_SG)\ **Post date:** [December 22, 2006, 6:08pm UTC](https://forums.speedlife.net/t/physics-question/102635/100 "2006-12-22T18:08:50Z")
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