YamaKiller

On first encounter this question, which has been showing up all over the Net, seems inane because the answer seems so obvious. However, as with the infamous Monty-Hall-three-doors-and-one-prize-problem (see The Straight Dope: "On Let's Make a Deal" you pick Door #1, 02-Nov-1990), the obvious answer is wrong, and you, Berj, are right--the plane takes off normally, with no need to specify frictionless wheels or any other such foolishness. You're also right that the question is often worded badly, leading to confusion, arguments, etc. In short, we've got a topic screaming for the Straight Dope. First the obvious-but-wrong answer. The unwary tend to reason by analogy to a car on a conveyor belt--if the conveyor moves backward at the same rate that the car's wheels rotate forward, the net result is that the car remains stationary. An aircraft in the same situation, they figure, would stay planted on the ground, since there'd be no air rushing over the wings to give it lift. But of course cars and planes don't work the same way. A car's wheels are its means of propulsion--they push the road backwards (relatively speaking), and the car moves forward. In contrast, a plane's wheels aren't motorized; their purpose is to reduce friction during takeoff (and add it, by braking, when landing). What gets a plane moving are its propellers or jet turbines, which shove the air backward and thereby impel the plane forward. What the wheels, conveyor belt, etc, are up to is largely irrelevant. Let me repeat: Once the pilot fires up the engines, the plane moves forward at pretty much the usual speed relative to the ground--and more importantly the air--regardless of how fast the conveyor belt is moving backward. This generates lift on the wings, and the plane takes off. All the conveyor belt does is, as you correctly conclude, make the plane's wheels spin madly. A thought experiment commonly cited in discussions of this question is to imagine you're standing on a health-club treadmill in rollerblades while holding a rope attached to the wall in front of you. The treadmill starts; simultaneously you begin to haul in the rope. Although you'll have to overcome some initial friction tugging you backward, in short order you'll be able to pull yourself forward easily. As you point out, one problem here is the wording of the question. Your version straightforwardly states that the conveyor moves backward at the same rate that the plane moves forward. If the plane's forward speed is 100 miles per hour, the conveyor rolls 100 MPH backward, and the wheels rotate at 200 MPH. Assuming you've got Indy-car-quality tires and wheel bearings, no problem. However, some versions put matters this way: "The conveyer belt is designed to exactly match the speed of the wheels at any given time, moving in the opposite direction of rotation." This language leads to a paradox: If the plane moves forward at 5 MPH, then its wheels will do likewise, and the treadmill will go 5 MPH backward. But if the treadmill is going 5 MPH backward, then the wheels are really turning 10 MPH forward. But if the wheels are going 10 MPH forward . . . Soon the foolish have persuaded themselves that the treadmill must operate at infinite speed. Nonsense. The question thus stated asks the impossible -- simply put, that A = A + 5 -- and so cannot be framed in this way. Everything clear now? Maybe not. But believe this: The plane takes off. airplane airplane 2

if my bike was on a treadmill at the bottom of the hill and you strapped a J.A.T.O. (jet engine)bottle on me would I move then...Yes...does not matter what my wheels are doing the turd would fly

that is the one point I am trying to make. If the conveyor belt is measuring aircraft speed and it sees the plane is going 300 mph and it spins backwards 300 mph, the aircraft must be moving forward to get that measuement. It must be moving thru the air at 300 mph to have it measured thru the pitot tube. It does not measure wheel speed so it must be flying

forward or backwards don't matter. if the speed of the aircraft is 300mph that is measured by the aircraft moving thru the air at 300 mph not measured by wheel speed even if the wheels are touching the ground(conveyor belt). If the aircraft is moving thru the air at 300 mph = LIFT like we have anything better to do while waiting to get back out there

ex aircraft engineer...absolutly.. get to work anyway...you need to be builing something to beat me

it will fly if the engine is pushing/pulling it. The speed of the aircraft is measured thru the pitot tube which is airspeed not ground speed. If the plane is going 300 knots, it does not matter what the wheels are doing (they could be spnning 1000mph). If the wheels were driving the plane like a car then it would sit still and not move forward but the jet or prop is moving the plane to speed thus creating lift. an example on the opposite side would be if the wheels don't turn can the plane take off..of course.you could be on ice and the wheels locked but the plane still moves forward creating lift. also, look at a harrier(sp) its wheels could be spinning on a convayor and it would still take off.

it will without a doubt take off. the conveyor will just double the speed of the wheels. It is propulsion that moves the plane forward giving it lift, not drive wheels (i.e. like a car with wings.)

just talked to Mercades(sp) and she said she would refund my money now

I called them and they said so what. Live and learn i guess. I will not do business there anymore.

I will be there from the 16th to the 26..see ya out there

I am in the wrong field I guess. Getting paid to camp, race at the drags and drive film crews around Dumont sounds awesome. I think I will apply for thier job. Since they seem to be giving rides now I think I will leave my gas and rhino at home and use the tax payers money to have fun at Dumont

DARKNESS??? its a friggen city out there but I know what you mean

I like the new spot. It was getting way too crowded at the old spot. Made it very difficult to get by sometimes with the TH. You would have to get real close to the end of the sand finger and a lot of people were getting stuck. It was a good landmark but to congested

I did not take any offense by your comment. I knew not everyone would agree with me but just wanted to say something on here about it. Everyone has thier own opinion like me. I still enjoy going out and would never change that. I have been out there before and not even went riding...just love being out there.. I will be out there for 11 days on T-day. Friday before till monday after

ynot, Thanks for your info. If you look at the first sentenance in my post I said what can we(me) do. I was not complaining and wanting someone else to fix it and leave me alone. I just wanted to hear responses from people. Just bored and venting. And when you say GET INVOLVED, I do with things that I believe I can help with like trash pickup. I personally don't think anything will help with what I was complaining about. There really is no way to fix STUPIDITY and DISRESPECT which is what it really is. only way to really fix the problem of camp racers is have 50 leo's parked out there in every area with radar guns and I for one don't want that. Like I said I would rather see no leo's.

I know what your saying pete. But not go out on a holiday weekend..NEVER!!!..we go out about every 2 weeks but never miss a holiday. I usually don't complain but when our buddy got a ticket for something so dumb it pissed me off. My honest opinion is I wish there were no leo's and we could just go have fun like it used to be but I know it will never be like that again with so many people. And I'm not really mad....love the crowds and parties, just sometimes feel like we are wasting time and money on leo's. Can't wait till t-day p.s. just bored sitting at home sick today so just wasting time

almost forgot.. Is it possible to sell NOS and alcohol (racing)

yea...time they could have spent taking care of real problems

Gotta vent a little so here goes. Just wondering if anybody else feels this way and what we can do. This last weekend (Halloween weekend) I had some major problems with stuff that happened out there. Now I know the rangers/leo's have a lot going on and are very busy but I just don't understand some things. 1. I thought they were going to enforce the no staking off the finger dunes. There were still quite a few camps that did this. I did notice that some people just used cones and caution tape which in my mind is still unacceptable but my opinion only but there were still a lot of staking going on. Like I said I know the rangers are busy but this was up all weekend so they could have done or said something to these people. 2. Camp/flat area racing was way out of hand this weekend and nothing done. We ended up a little close to the main road going to comp hill then usual but we dealt with it. I know people are excited but 40-60 mph past us sometimes doing wheelies is crazy. We had our camp coned off around us and when we would go to leave camp it was like trying to pull out onto 15. Several of us almost got hit just inching out from the camp. The worst thing is we saw rangers sitting there watching these people and doing nothing. Just parked for 30 mins to an hour just watching. We even had somebody go talk to the rangers about controlling the area a little better and they did nothing. Now I don't normal b!tch about these things but we had a fellow camper 2 weeks ago get pulled over out at comp hill who hopped in his rhino and drove about 50 feet away about 3 mph and his passenger had an open beer. Leo pulled him over and gave them a open container ticket. almost got a seatbelt ticket too. While they were sitting there with leo a quad drives by with 2 people and no helmets and my buddy was like your giving me a ticket and letting them go and he did. Now I know technically he did break the law but He was not doing anything crazy or stupid. I feel like they are being harsh on simple easy things to give tickets on but letting the big stuff go. They said they are going to start pulling people over for no seatbelt and you get a ticket like a car. This is getting ridiculous. I thought we were offroad?? It just seems like the speeders are too much work to go after so we'll get the easy ones. Like I said before I know they are busy but this stuff is right in front of thier face. Just my opinion but I think the 3 biggest problems they need to work on is: 1. Camp racers 2. Staking the finger dunes 3. people leaving trash ( I pulled up there Thur @3pm and there was a whole camp that left all thier garbage around the fire from the weekend before I guess that we picked up)

There is always going to be people that think your too high priced. But I think the majority of us duners know what a great service the vendors provide. I know a lot of people including myself that have bought stuff out there knowing it is higher priced and getting back to camp and thinking yeah I could of got it cheaper on ebay or in town but do you think it stopped us from buying. Hell no. I know you have to make money for coming out there and I would pay double or triple or whatever to keep riding for the weekend. Not only do I want to continue to ride but I want to support you for bieng there. Some people just don't get it. If you dont make money, you won't be there then we are really screwed. You can always tell people yeah you could save 50 or 60 bucks on that CDI.. I'll let you use my internet access and order it right now..have fun this weekend knowing you saved some money but after spending 500 or 600 dollars on gas food and everything else you are going to enjoy sitting around not riding. If you can't tell, this is a sore subject for me. I am in business for myself and people just don't understand. Not only are you providing a product but also a great service and that makes the price higher. Anyway, just keep doing a great job bringing out as much stuff as you can and don't let a few tight wads ruin it. You gotta stay in business and make money. Thanks for being out there

I feel sorry for most of the people going out this weekend :peek: ......... .......... .......... Because I am headed out now.. :peek: :freakin_nuts: See you guys out there

Just to let everyone know I went to get a couple 08 stickers and the price has gone up to $25

Hey CaptNkllm, Remember me? pulled you out at the night drags and I have the KFX. Talked to you at the hill this weekend. Just for the record, mine is all bolt on...bolt on NOS bottle, bolt on motor, bolt on heads, etc... nice meeting you again and we'll see you out there.

could have been better at the top but some rv slowed me down and i lost it down to 45 2 nd gear. if I don't have anyone in front of me I can pull the top of the hill at 60. I am really impressed with the dodge. Getting the transmission upgraded next week with shift kit and billet torque converter. Should be even better.