I know my response will be buried deep within the hundreds of pages this thread will accumulate, but here's the rub.

Aircraft will take off.
You can accelerate the hell out of the 'treadmill runway' and all will impart on the aircraft is a negligible amount of angular momentum in the -x direction (opposite thrust) about the wheels causing the nose to dip (easily countered with elevator angle). Aicraft will move forward, generate flow over the airfoils, generate lift per Bernoulli's equation, airborne.

Bullets will fall at the exact same moment unless you were able to achieve orbital velocity with the fired bullet (ignoring wind resistence). This bullet would be traveling traveling across the surface of the earth (provided you fired it above any mountains in the path) so that gravity would pull the bullet into an arc therby achieving an orbit of Re+drop height. As for the argument of air resistence causing the fired bullet to land faster than the dropped one, the air resistence would limit the distance traveled, but not the hangtime with regards to the dropped bullet (remember both bullets are experiencing resistence proportional to their speed).

Don't believe me, look at my profile to see what I do for a living.

Did someone email this question to these guys? I want to see them build a model to test it.

Excellent, despite being a janitor, you have a better grasp of this than the remaining hold outs.

You mean like the 23 posts before yours suggested?



It was already agreed that they would not have to test it...simple logic solves it.

No experiment is required.

The conveyor belt is designed to confuse you...its a red herring.

Your speed on a tread mill is zero...your EQUIVALENT speed is what ever the speedometer says.

If you are on a tread mill, and I yank you forward with a rope...NO MATTER HOW FAST THE TREAD MILL BELT GOES...you WILL move forward....by the distance the rope pulled you.

If that's unclear...you may NEVER get it.

Graham, you're funny.

you know, this is sad. there are more posts here then the phat chick friday thread. if everyone who posted here posted one good picture in the other thread, we would be set.

I would like to apologize to everyone I insulted last night. I was frustrated and took it out on the people here. It does seem to me now that the people that don't get it are just pretending to not get it in order to get people like me irritated. I get the joke now and feel much better. I just feel that people that I have so much in common with should be smarter than the average bear and when it seems to be otherwise, it tends to get me pissed. Kind of the way I feel when somebody in the Army does something stupid. I feel it reflects on me personally. I will try in the future to not let that happen.

So... Here's a new question!

Lets say you're on a train moving along the tracks at 12mph. Let's also say that all of the exit doors on the train are open. The doors between the train cars are open too. It has become apparent to you that the train is headed for a ravine and the bridge is out. Your only options are A and B. Which option is safest?

A) Jump out of a side exit door, hit the ground and roll, keeping your momentum rolling forward in the direction of the train.

B) Sprint toward the rear of the train, trying your best to approximate 12mph, and jump out of the back.

Where's the treadmill?

Half nudie girl on treadmill

I wouldn't say I was arguing any side to piss you off or anyone else.

It is amazing that regardless of how civil one conducts themselves in any debate on here, there are those that instantly sink to nothing but insults. (I don't mean you either. You have also came back and apologized like a gentleman).

As far as this subject goes, I clearly stated early on that I was wrong in my initial responses and that I was going to play devil's advocate.

You shouldn't feel that anyone else's responses are a reflection on you.

I'll continue to play the devil's advocate. So, does the plane actually fly?

I read every response in this thread and can't find the devil's advocate reference. Could you point me towards the page number it is on?

Actually, I did see that...but I thought he just went back to the dark side...as I thought on this one, the Devil was well represented already.

Coals to New Castle so to speak.

"Lets say you're on a train moving along the tracks at 12mph. Let's also say that all of the exit doors on the train are open. The doors between the train cars are open too. It has become apparent to you that the train is headed for a ravine and the bridge is out. Your only options are A and B. Which option is safest?

A) Jump out of a side exit door, hit the ground and roll, keeping your momentum rolling forward in the direction of the train.

B) Sprint toward the rear of the train, trying your best to approximate 12mph, and jump out of the back.
"

Well, for this one, its more like the the train is the tread mill.



You are comparing your impact with stationary ground in two scenarios...one leaping sideways to your direction of travel...one leaping backwards opposite your direction of travel.

This one's easy for me... Jump out the side door. Why? Because there's less distance to it, and frankly, I want to reduce the risk of falling down when I'm trying to "approximate" 12 mph, and end up riding the damn thing to the bottom of the cliff.

Besides, it's 12 mph.. I've crashed on a mountain bike going faster than that! Avg. human walks at 5 mph, so 12 isn't really any big deal at all...

12mph is what 5 min per mile, I am guessing there isn't anyone on the this board running sub 5's.

A brief summary of some things I have said....

Page 10...
I wasn't referring to the tires or anything related to the wheels in that particular comment.

I also believe that I was wrong for saying definitively that the aircraft in this scenario would not obtain flight.

I do however see a problem with the scenario. I can't say it would or would not take flight at this point.

We can discuss it further tomorrow or another time.

Page 19...
If they are serving chicken for dinner, the plane will definitely fly.

If that horrible airline vegetable lasagna is on the menu, it will not take off.

Page 19...
You obviously haven't read the entire thread.

I am no longer dedicated to the position that it will not fly.

Page 21...
Let me play devils advocate here Rock....

I was out of the thread for a number of pages and people were beating on a few other users.

I'm neutral on the plane scenario. Will that piss some people off?

there's a TON of people on this board who could run that fast for a short distance.

I was curious how many people would think it would be a bad idea to run out the back. If I could sprint 12mph out the back door, I'd essentially "plop" down in place on the tracks since my relative speed to the ground would be zero.

Except that this would be a sprint, not a marathon where 12mph equates to a 6.8 40 time (ver attainable). Even if you didn't achieve that speed, you would only experience the difference between your sprint and the 12mph which would be at worst similar to stepping off a moving sidewalk.
Now, if proximity is an issue (ravine is coming up quick) then maybe a sprint down the train won't work and at worst you get some rock burns and such from a dive out the side (sprinters can maintain 20mph speeds so a fall wouldn't be too severe from 12mph).

This situation needs worse consequences than 12mph to be a viable debate.

My thought is that even if I match the 12 mph - I will be falling straight down.

The trick of course would be how to DO that...as, if it were going to work that way....I'd see the exact same thing outside through the train car window as I ran, and the train ran out from under me.



I have NO idea how I'd run in place as the train went out from under me, especially considering I only have one leg, etc.

OK - So even if I DID manage to stay in place as the train rolled out from under me...I'd fall straight down...maybe 4'? Onto a rail road track...

If I went out the side and rolled, I would contact the ground at around 12 mph...but, rolling would absorb most of the impact.

Smart people scare me.

Yeah a sub 5 sprint would be pretty easy and I realized that...just stirring the pot to avoid work.

Another (probably futile) attempt at an analogy.

There's a car in a northbound lane traveling at 60 mph, and a car in the southbound lane traveling at 60 mph. They have no effect on each other.

Now suppose the highway is perfectly straight and the southbound car has an enormous vertical board attached to the left side, miles long. The northbound car has a set of non-geared, free-spinning wheels on its left side. Supposing that both cars drive straight and the wheels remain in constant contact with the board, what happens

Each car travels at 60 mph, the wheels on the side travel at a rate of 120 mph. If they have a standing start and accelerate at the same rate, they still would be able to move in opposite directions and the free-spinning wheels would spin at twice the rate of the drive tires.

Hence, the cars are not "equal and opposite forces" because they are not opposing, just like the conveyor is not opposing the plane.

You feel fairly safe here, don'tcha?

Neutral?

You mean you STILL don't know it would fly, but are just trying to avoid pissing people off?

By pretending to think it would NOT fly?



Still, somehow, that's endearing.