Will the plane take off? v. Mythbusters!!! (VIDEO on Page 38)

[DaX]

If it moves forward on the conveyor belt, yes. If that's the case, then the conveyor belt is as good as it not even being there.

[speedminded]

If it moves forward on the conveyor belt, yes. If that's the case, then the conveyor belt is as good as it not even being there.

lol EXACTLY! It's free spinning wheels, it doesn't matter how fast or even what direction the conveyor belt is spinning...the plane will still propel itself forward just as it would any other time.

[On_Her_Face]

For all you doubters:

If they can prove that the plane moves forward on a conveyor belt, would you agree that given a long enough belt, it would take off?

yes or no?

im still taking that bet with you.

[DaX]

lol EXACTLY! It's free spinning wheels, it doesn't matter how fast or even what direction the conveyor belt is spinning...the plane will still propel itself forward just as it would any other time.

My whole thought process was that they would be matching the speed of the belt with that of the airplane but in the opposite direction, thus canceling out all forward motion. If that was the case you could get away with a conveyor belt as short as the airplane's wheelbase.

I'm still saying no.

[Wurm]

dont forget ruiner i got 5 on no

[speedminded]

My whole thought process was that they would be matching the speed of the belt with that of the airplane but in the opposite direction, thus canceling out all forward motion. If that was the case you could get away with a conveyor belt as short as the airplane's wheelbase.

I'm still saying no.

A planes speed isn't measured at the wheels. Nobody cares how fast the wheels are spinning, it's the speed of the air at which the plane passes through and is measured by the ram pressure through a pitot tube.

[BABY J]

**** won't take off.


~ runs

[Julio]

I have changed my mind... The plane will take off.

[bigdare23]

Decided to talk a few you back to school. I copied from my Thermodynamics textbook.

Gas turbines are particularly suited for aircraft propulsion because of their favorable power-to-weight ratios. The turbojet engine is commonly used for this purpose. As illustrated in Fig. X.XX, this type of engine consists of three main sections: the diffuser, the gas generator, and the nozzle. The diffuser placed before the compressor decelerates the incoming air relative to the engine. A pressure rise known as the ram effect is associated with this deceleration. The gas generator section consists of a compressor, combustor, and turbine, with the same functions as the corresponding components of a stationary gas turbine power plant. In a turbojet engine, the turbine power output need only be sufficient to drive the compressor and auxiliary equipment, however. The gases leave the turbine at a pressure significantly greater than atmospheric and expand through the nozzle to a high velocity before being discharged to the surroundings. The overall change in the velocity of the gases relative to the engine gives rise to the propulsive force, or thrust. Some turbojets are equipped with an afterburner, as shown in Fig X.XX. This is essentially a reheat device in which additional fuel is injected into the gas exiting the turbine and burned, producing a higher temperature at the nozzle inlet than would be achieved otherwise. As a consequence, a greater nozzle exit velocity is attained, resulting in increased thrust.

So read this before you vote, so you wont make yourself look stupid

[Kdanzig]

When is this airing exactly??

[Kyle]

Although I said yes and I am 99.99% sure its right I wannna ask some aerospace engineers what they think. ~knocks on roommates door~

[bigdare23]

My whole thought process was that they would be matching the speed of the belt with that of the airplane but in the opposite direction, thus canceling out all forward motion. If that was the case you could get away with a conveyor belt as short as the airplane's wheelbase.

I'm still saying no.

You are semi-correct. Go back to your FBD days. The treadmill will be producing a equal yet opposite force on the wheel due to frictions (rolling motion), but that doesn't include the force of the thrust acting on the plane itself.

[bigdare23]

Let B1 and B2 be two rigid bodies in motion. We define rolling to exist between B1 and B2 if during their motion:
1. A continuous sequence of points on the surface of B1 comes into one-to-one contact with a continuous sequence of points on the surface of B2.

2. At each instant during the interval of the motion, the contacting points have the same velocity vector.


Note that according to this definition there can be no slipping or sliding between the surface B1 and B2 if rolling exists.

So if you label the wheel B1 and the treadmill B2 the point where the wheel touches the treadmill the velocities would be the same. This would cause the plane to remain still on the tread mill. Now, incorporate the thrust. Since the treadmill is moving at a constant velocity, thrust from the engine would force the wheel to overcome the velocity of the treadmill, causing forward motion, and ultimately lead to lift.


I deserves some positive reps

[Ruiner]

My whole thought process was that they would be matching the speed of the belt with that of the airplane but in the opposite direction, thus canceling out all forward motion. If that was the case you could get away with a conveyor belt as short as the airplane's wheelbase.

I'm still saying no.

You are saying no, the plane won't advance forward on the treadmill and won't take off?

[Ruiner]

When is this airing exactly??

12th (Wednesday) @ 9pm? Maybe 8pm, but I think 9pm.

[Ruiner]

dont forget ruiner i got 5 on no

On "no" that it won't advance down the treadmill and/or that it won't take off?

Noted

[RandomGuy]

20$ on it'll take off and/or move forward along the conveyor... anyone want to take me up on that?

if you win i'll paypal you the funds immediately

[speedminded]

20$ on it'll take off and/or move forward along the conveyor... anyone want to take me up on that?

if you win i'll paypal you the funds immediately

Me too but make it $200 and any doubters have to be in agreement 48 hours before the show airs.

[Nittanys1]

i want in that it will take off!!!

[Echonova]

I can't wait for the 12th so this thread will die.

[Nittanys1]

ohh it will only get bigger!

[BABY J]

http://www.importatlanta.com/forums/...&postcount=562

[Ruiner]

Back when I had my 911 turbo, I put that up as a bet. NOBODY took it.

What concerns me is that almost half of IA.com are not the brightest. This isn't a hard question, people.

Here is another one:

If a plane is on an indefinitely slippery surface, will it take off? What if that slippery surface is moving? Will it still take off?

[magneto198]

sounds cool, ill watch

[speedminded]

This just in...

The episode, which airs in December, finds Savage and Hyneman tackling a question baffling everyone from bloggers to pilots: If a plane is traveling at takeoff speed on a conveyor belt, and that conveyor belt is matching the speed in reverse, can the plane take off?

``We put the plane on a quarter-mile conveyor belt and tested it out,'' says Savage about the experiment using a pilot and his Ultralight plane. ``I won't tell you what the outcome was, but the pilot and his entire flight club got it wrong.''

[VooDooXII]

If a plane is on an indefinitely slippery surface, will it take off? What if that slippery surface is moving? Will it still take off?

Same concept...because the component responsible for propelling the plane forward is not in contact with the surface it's moving along. It'd be the same as if the plane was hovering.

[BKgen®]

lol this is gonna be the highest rated mythbusters ever. There are gonna be so many ppl watchin this sh*t.

[Wurm]

no that it wont take off ruiner. In theory it should take off but i dont trust human error

[Ruiner]

This just in...

The episode, which airs in December, finds Savage and Hyneman tackling a question baffling everyone from bloggers to pilots: If a plane is traveling at takeoff speed on a conveyor belt, and that conveyor belt is matching the speed in reverse, can the plane take off?

``We put the plane on a quarter-mile conveyor belt and tested it out,'' says Savage about the experiment using a pilot and his Ultralight plane. ``I won't tell you what the outcome was, but the pilot and his entire flight club got it wrong.''

I'm going to bet that they all thought that it "wouldn't" take off. Ahahahha

URL link to this?

[Ruiner]

no that it wont take off ruiner. In theory it should take off but i dont trust human error

Human error? Listen, if someone TRULY knows that it should take off (which it will), then Mythbusters will not get it wrong. I assure you on this. However, good luck!

[speedminded]

I'm going to bet that they all thought that it "wouldn't" take off. Ahahahha

URL link to this?

From their local paper... http://www.mercurynews.com/food/ci_7...nclick_check=1 (The article is a month old)

[Clegger]

^sign in?

[Jaimecbr900]

My answer is that IF the plane creates enough thrust to overcome the conveyor and get the plane moving forward, then it should fly. IF the conveyor is at a constant speed, then it should be easier for the plane to overcome with enough thrust. IF the conveyor adjusts speed up in accordance to the amount of thrust, then the plane can't move forward and therefore it won't be able to fly.


Too many "IF's", but that's my take on it.

Are we gonna do wings and beer somewhere so the winners can gloat?

[speedminded]

My answer is that IF the plane creates enough thrust to overcome the conveyor and get the plane moving forward, then it should fly. IF the conveyor is at a constant speed, then it should be easier for the plane to overcome with enough thrust. IF the conveyor adjusts speed up in accordance to the amount of thrust, then the plane can't move forward and therefore it won't be able to fly.


Too many "IF's", but that's my take on it.

Are we gonna do wings and beer somewhere so the winners can gloat?

If you tied a rope to the front of the ultralight and stood on either side of the conveyor belt your hand alone could easily overcome the conveyor with virtually no effort

[BKgen®]

lol, i realize this. Trust me, growing up as a pilot's son, the last thing i need is a lesson about aerodynamics.

here's how the actual problem is worded:

Suppose a plane is on a runway that acts as a conveyer belt. The conveyor belt is as long as a typical runway. The plane moves in one direction, while the conveyer moves in the opposite direction at the same speed as the plane. The wheels of the plane are free-rolling. Will the plane be able to take off?

Notice it says that the conveyor belt is the same size as a typical runway. SO, we know that if the plane were to move forward, there would be plenty of room for it to take off.

Now, i realize that you guys are saying the wheels will roll as the conveyor belt passes by. Well i'm not sure what kind of planes you guys are talking about, but i've never seen one powered by its wheels lol, so the wheels don't matter.

In that case, whether its a moving conveyor belt or a stationary runway, the jet's engines (or the plane's props) will push the plane forward at normal speed as if it were on a regular runway, causing it to get air under its wings.

kthxbye

quoted so i can say i told ya so

[Jaimecbr900]

If you tied a rope to the front of the ultralight and stood on either side of the conveyor belt your hand alone could easily overcome the conveyor with virtually no effort

If that's so, then it's going to take off.

[Psycho]

I think the plane is going to move forward on the treadmill just like it would on regular tarmac. The plane isn't going to sit still just because the wheels are moving backward.

[Psycho]

quoted so i can say i told ya so

Oh, you already said what I just did.

All that effort for nothing.

[Ruiner]

A. Today is the day, bitches!

B. I created a nice drawing for some of you who might be confused about the rotation of the wheels... The wheels spin the same way! How is that going to hold the plane back?

[bigdare23]

I really sat down for 30mins using my Mechanic Engineering knowledge to explain why it would take off.

But my post just got kicked to the side


{shakes head} I give up.