# Physics Question: Fan + Sailboat? **URL:** \ **Category:** NYSpeed Off Topic\ **Created:** [May 8, 2009, 11:47am UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503 "2009-05-08T11:47:37Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![tpgsr](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/tpgsr/32/7374_2.png) [@tpgsr](https://forums.speedlife.net/u/tpgsr)\ **Post date:** [May 8, 2009, 1:06pm UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503/41 "2009-05-08T13:06:53Z")
:picard: you forgot the fan micah. ---
**Author:** ![sobo](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/sobo/32/5267_2.png) [@sobo](https://forums.speedlife.net/u/sobo)\ **Post date:** [May 8, 2009, 1:07pm UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503/42 "2009-05-08T13:07:16Z")
Real question is, what is the MPG? ---
**Author:** ![Fry](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/fry/32/7284_2.png) [@Fry](https://forums.speedlife.net/u/Fry)\ **Post date:** [May 8, 2009, 1:09pm UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503/43 "2009-05-08T13:09:37Z")
Yay! Use a windmill to convert wind power to electricity to power the fan to move the boat forward! Anyways, I give myself a 1 week self ban! šŸ˜‰ ---
**Author:** ![snowracer101](https://avatars.discourse-cdn.com/v4/letter/s/258eb7/32.png) [@snowracer101](https://forums.speedlife.net/u/snowracer101)\ **Post date:** [May 8, 2009, 1:10pm UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503/44 "2009-05-08T13:10:04Z")
> [@sobo](#): > > Real question is, what is the MPG? kpg knots per gallon ---
**Author:** ![yamba6](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/yamba6/32/5161_2.png) [@yamba6](https://forums.speedlife.net/u/yamba6)\ **Post date:** [May 8, 2009, 1:11pm UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503/45 "2009-05-08T13:11:34Z")
im going with the electric motor that you usually have as a back up. it moves now. ---
**Author:** ![TurboTSi](https://avatars.discourse-cdn.com/v4/letter/t/22d042/32.png) [@TurboTSi](https://forums.speedlife.net/u/TurboTSi)\ **Post date:** [May 8, 2009, 1:12pm UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503/46 "2009-05-08T13:12:26Z")
> [@sedlmeier101](#): > > kpg > > knots per gallon nmpg isnā€™t itā€¦ nautical miles per gallon? knot is a measurement of speed. ---
**Author:** ![JayS](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jays/32/15375_2.png) [@JayS](https://forums.speedlife.net/u/JayS)\ **Post date:** [May 8, 2009, 1:13pm UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503/47 "2009-05-08T13:13:17Z")
> [@Fry](#): > > Yay! Use a windmill to convert wind power to electricity to power the fan to move the boat forward! > > Anyways, I give myself a 1 week self ban! šŸ˜‰ The Rube Goldberg solution to the energy crisis? ---
**Author:** ![micah](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/micah/32/7257_2.png) [@micah](https://forums.speedlife.net/u/micah)\ **Post date:** [May 8, 2009, 1:20pm UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503/48 "2009-05-08T13:20:47Z")
![http://www.micahweber.com/shutup.JPG](http://www.micahweber.com/shutup.JPG) ---
**Author:** ![Pass\_McGass](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/pass_mcgass/32/7616_2.png) [@Pass\_McGass](https://forums.speedlife.net/u/Pass_McGass)\ **Post date:** [May 8, 2009, 1:23pm UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503/49 "2009-05-08T13:23:32Z")
> [@Willybeen](#): > > youā€™re all wrong > [http://www.youtube.com/watch?v=0CrXvOKPymk](http://www.youtube.com/watch?v=0CrXvOKPymk) WHAT THE FUCK ---
**Author:** ![Geoff](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/geoff/32/6104_2.png) [@Geoff](https://forums.speedlife.net/u/Geoff)\ **Post date:** [May 8, 2009, 1:25pm UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503/50 "2009-05-08T13:25:38Z")
lol, newton must have been out sick that day ---
**Author:** ![tpgsr](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/tpgsr/32/7374_2.png) [@tpgsr](https://forums.speedlife.net/u/tpgsr)\ **Post date:** [May 8, 2009, 1:26pm UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503/51 "2009-05-08T13:26:59Z")
> [@Pass McGass](#): > > WHAT THE FUCK I almost want to discount that video as the frictional force on the wheels is nothing compared to the force of water on the hull. The car moves pretty slow, and I am not sure of what a boat would do. Post another video using the appropriate scenario. ā€œTo every action there is always opposed an equal reaction: or the mutual actions of two bodies upon each other are always equal, and directed to contrary parts.ā€ ---
**Author:** ![Maksim2000](https://avatars.discourse-cdn.com/v4/letter/m/dec6dc/32.png) [@Maksim2000](https://forums.speedlife.net/u/Maksim2000)\ **Post date:** [May 8, 2009, 1:31pm UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503/52 "2009-05-08T13:31:52Z")
> [@tpgsr](#): > > I almost want to discount that video as the frictional force on the wheels is nothing compared to the force of water on the hull. The car moves pretty slow, and I am not sure of what a boat would do. > > Post another video using the appropriate scenario. > > ā€œTo every action there is always opposed an equal reaction: or the mutual actions of two bodies upon each other are always equal, and directed to contrary parts.ā€ Canā€™t see the video at work, but: Ever seen thrust reverser on the old jets? I think between the sail and the fan you can get the same effect going. it is less efficient that just pointing the fan backwards,but it could generate some thrust. ---
**Author:** ![Pass\_McGass](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/pass_mcgass/32/7616_2.png) [@Pass\_McGass](https://forums.speedlife.net/u/Pass_McGass)\ **Post date:** [May 8, 2009, 1:32pm UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503/53 "2009-05-08T13:32:07Z")
Was it on wheels though? It looked to me that it was on some kind of low-friction surface and it slid atop it. ---
**Author:** ![Paulo](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/paulo/32/7328_2.png) [@Paulo](https://forums.speedlife.net/u/Paulo)\ **Post date:** [May 8, 2009, 1:45pm UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503/54 "2009-05-08T13:45:23Z")
> [@Pass McGass](#): > > Was it on wheels though? It looked to me that it was on some kind of low-friction surface and it slid atop it. Itā€™s a glide. The surface of that rail has holes in it that have air pumped through them to reduce friction. Pretty much like an air hockey table. ---
**Author:** ![Pass\_McGass](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/pass_mcgass/32/7616_2.png) [@Pass\_McGass](https://forums.speedlife.net/u/Pass_McGass)\ **Post date:** [May 8, 2009, 1:48pm UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503/55 "2009-05-08T13:48:17Z")
> [@Paulo](#): > > Itā€™s a glide. The surface of that rail has holes in it that have air pumped through them to reduce friction. Pretty much like an air hockey table. :io: ---
**Author:** ![Paulo](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/paulo/32/7328_2.png) [@Paulo](https://forums.speedlife.net/u/Paulo)\ **Post date:** [May 8, 2009, 1:48pm UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503/56 "2009-05-08T13:48:59Z")
^Hahaha, god damn it! The reason that small scale model is working is because the ā€œsailā€ is so close to the fan that it is pretty much just redirecting the wind for it. In this case, a higher percentage of wind is redirected in the opposite direction, giving it a slight foward propulsion. ---
**Author:** ![JayS](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jays/32/15375_2.png) [@JayS](https://forums.speedlife.net/u/JayS)\ **Post date:** [May 8, 2009, 1:59pm UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503/57 "2009-05-08T13:59:28Z")
> [@Pass McGass](#): > > Was it on wheels though? It looked to me that it was on some kind of low-friction surface and it slid atop it. It really doesnā€™t matter how low friction it was. If itā€™s a boat it may not move very fast but it will move, which is certainly not what most of us thought. The analogy of the jet ski reverse thruster is a good one. What weā€™re forgetting to account for is the air that reflects back off the sail and creates wind blowing the opposite direction of the fan, AKA, THRUST. ![http://i224.photobucket.com/albums/dd75/jsears77/ssfry.jpg](https://canada1.discourse-cdn.com/flex034/uploads/speedlife/original/3X/c/b/cbad17b990b495b5c83a4beaae9b13c63a402f21.jpeg) ---
**Author:** ![Pass\_McGass](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/pass_mcgass/32/7616_2.png) [@Pass\_McGass](https://forums.speedlife.net/u/Pass_McGass)\ **Post date:** [May 8, 2009, 2:04pm UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503/58 "2009-05-08T14:04:48Z")
> [@JayS](#): > > It really doesnā€™t matter how low friction it was. If itā€™s a boat it may not move very fast but it will move, which is certainly not what most of us thought. The analogy of the jet ski reverse thruster is a good one. I was just contesting tpgsrā€™s statement about it being on wheels. > [@tpgsr](#): > > I almost want to discount that video as the frictional force on the wheels is nothing compared to the force of water on the hull. The car moves pretty slow, and I am not sure of what a boat would do. ---
**Author:** ![pirite](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/pirite/32/5308_2.png) [@pirite](https://forums.speedlife.net/u/pirite)\ **Post date:** [May 8, 2009, 2:16pm UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503/59 "2009-05-08T14:16:38Z")
so who wants to submit this to mythbusters? ---
**Author:** ![Zong](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/zong/32/7580_2.png) [@Zong](https://forums.speedlife.net/u/Zong)\ **Post date:** [May 8, 2009, 3:07pm UTC](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503/60 "2009-05-08T15:07:12Z")
> [@Paulo](#): > > The reason that small scale model is working is because the ā€œsailā€ is so close to the fan that it is pretty much just redirecting the wind for it. In this case, a higher percentage of wind is redirected in the opposite direction, giving it a slight foward propulsion. :io: [Previous page](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503.md?page=2) [Next page](https://forums.speedlife.net/t/physics-question-fan-sailboat/67503.md?page=4)