Plane on a Treadmill

[herbicide]

Technically, the power (thrust) of the jet engines are overcoming the friction between the treadmill speed and the wheels. Otherwise the plane would reverse and fall off the treadmill Nothing more, nothing less.

I am too lazy and 'enhanced' to read the entire thread.

 

[Wesley]

[ame=http://www.youtube.com/watch?v=-EopVDgSPAk]YouTube - Plane vs. Treadmill Solved![/ame]

 

[cmoneyr]

Just thought of a good comparison. Put the drive wheel of a car on a roller. You'll just sit and spin with no forward motion.

Not a good comparison, the drive wheels of a car DRIVE the car, hense the name. The wheels on a plane don't drive the plane forward.

 

[tim_redd]

Just as soon as you prove it true.

:biglaugh:

I thought you'd never ask.

It's quite simple really.

1/3 exactly equal 0.3333333~

No arguments?

1/3 + 1/3 + 1/3 = 1

No arguments?

0.3333333333~ + 0.333333333~ + 0.3333333333~ = 0.9999999999~

Therefore 1 must equal 0.9999999999~

No arguments?

I thought so...

 

[herbicide]

YouTube - Plane vs. Treadmill Solved!

I never saw the plane take off, I saw it crash into the front of the treadmill. Youtube is the end all be all of every scientific fact ever.

(I have only read page one and the end of this silly argument)

 

[CyPlainsDrifter]

I thought you'd never ask.

It's quite simple really.

1/3 exactly equal 0.3333333~

No arguments?

1/3 + 1/3 + 1/3 = 1

No arguments?

0.3333333333~ + 0.333333333~ + 0.3333333333~ = 0.9999999999~

Therefore 1 must equal 0.9999999999~

No arguments?

I thought so...

Yes argument......

1/3 exactly equals 0.3333333~

:biglaugh::biglaugh::biglaugh: No.....

0.3333333~ never reaches 1/3..... that's what the ~ means.
Try this instead....... 0.3333333~ approaches 1/3
To infinity and beyond, Buzz!

 

[jbhtexas]

Futility. I want that board Brian. I've got a scale aircraft model with a 7ft wingspan and 1hp engine. You provide the treadmill and I'll bring my model. And whoever said they are an ME, you must have not got it at ISU. You would have never made it though phy 223.

Cool plane!! I have a fairly easy way to make a long "treadmill" for your plane. Get a roll of polyethylene or other plastic on a tube...something about 3" or more in diameter. Get a piece of 1/2" threaded rod about a foot longer than the roll is wide, and stick it through the center of the roll. Put a washer and nut on each end of the rod, center the rod in the tube, and tighten down the nuts (and use lock nuts so they don't come loose), so that when you turn the rod, you turn the roll.

Then, make a little wooden frame out of 2x4's to hold the roll of plastic parallel to the ground, and very close to the ground. Put a double nut on one end of the threaded rod, so that you can spin it with a 1/2" high speed electric drill and a socket.

Unroll the plastic, and then roll it back up with the high speed drill. It will probably be necessary to attach a 3/8" rod at the end of the plastic just to keep the plastic taut as it gets rolled up...

Get a friend to hold the frame, and one to run the drill...Instant "treadmill" runway!!

 

[singsing]

Not a good comparison, the drive wheels of a car DRIVE the car, hense the name. The wheels on a plane don't drive the plane forward.

It all comes down to friction and resistance. If you remove both (as the treadmill and rollers on a cars wheels will) you will not move forward. Is the treadmill to be mechanical to match the engines thrust or is it going to allow some resistance? Also, my plans for perpetual motion is a concept using buoancy of air in water with counter acting ballist tanks. Wrap your minds around that.

 

[CyPlainsDrifter]

I never saw the plane take off, I saw it crash into the front of the treadmill. Youtube is the end all be all of every scientific fact ever.

(I have only read page one and the end of this silly argument)

Doesn't matter that it didn't get airborne.... the point that should drive the argument home is the fact that the plane moved forward ~ the same speed with the treadmill STOPPED and with it running MANY times faster (in the opposite direction) than the speed of the plane. The treadmill is a distraction and has nothing to do with the motion of the plane.

 

[cmoneyr]

It all comes down to friction and resistance. If you remove both (as the treadmill and rollers on a cars wheels will) you will not move forward. Is the treadmill to be mechanical to match the engines thrust or is it going to allow some resistance? Also, my plans for perpetual motion is a concept using buoancy of air in water with counter acting ballist tanks. Wrap your minds around that.

Why would I want to hear your thoughts about perpetual motion if you can't grasp simple physics?

 

[Wesley]

Do not forget about the air temperature - less lift on a very hot day as the air expands. Is this treadmill outside in the heat of the day or is it in Brians basment?

The Mythbusters test may be outdoors. If Brian is going to try out a seven ft wingspan plane, he might have to move his treadmill outdoors also.

 

[iowast8fan]

Is this thread still going? Anyone who thinks the plane will stand still while using jet engines does not understand how jet engines make a plane move forward.
As long as those jet engines are running, it does not matter how fast a tread mill moves under the wheels. The plane is being pushed forward by the thrust of the jet engines. The you tube video shows it pretty clearly.

 

[herbicide]

Doesn't matter that it didn't get airborne.... the point that should drive the argument home is the fact that the plane moved forward ~ the same speed with the treadmill STOPPED and with it running MANY times faster (in the opposite direction) than the speed of the plane. The treadmill is a distraction and has nothing to do with the motion of the plane.

The problem with your argument is that is the law of conservation of energy. The treadmill is providing energy to the plane, the plane is using its energy from the propellers to overcome the inertia of this energy, which equals its own mass times the rate of acceleration, as well as any friction encountered by the treadmill and plane, which happen to be the wheels.

If the plane is not on a treadmill, it needs to overcome three (actually four) forces;

1. The inertia of its own mass (as discussed before)
2. Friction. This happens to be the wheels
3. Aerodynamic drag.
4. Gravity.

The reason the plane can go faster in the Youtube experiment is that it is not facing equal aerodynamic drag. Aerodymamic drag is an exponential force, as in the force encountered by an object at say, 100 mph is more than 2x the force than at 50mph. Because of this, the plane travels faster than it normally could, because the plane is providing more energy than the friction of the treadmill and wheels. Otherwise it would be a remote control car on stable ground, never being able to overcome its own inerta and friction

Most importantly, and in laymans terms, the youtube experiment showed that the treadmill never kept up with the acceleration of the plane (obviously) because the plane advanced in position versus the treadmill. That was the original question posted. In the youtube experiment, the treadmill could not keep up with the acceleration or speed of the plane, and never actually took off. There is no argument there.

 

[singsing]

I've got it now. Put an F-16 on its tail and with its thrust to weight ratio it will still lift off. Who started this thing anyway? I'm taking my headache to bed.

 

[herbicide]

Is this thread still going? Anyone who thinks the plane will stand still while using jet engines does not understand how jet engines make a plane move forward.
As long as those jet engines are running, it does not matter how fast a tread mill moves under the wheels. The plane is being pushed forward by the thrust of the jet engines. The you tube video shows it pretty clearly.

Jet engines, as well as propeller "engines" use pressure differential to apply power or force, IE they create a low pressure area and a high pressure area. This is what causes them to apply power/force, ie high pressure area vs. low pressure area = high pressure area moves to low pressure area to equalize force.

They adhere to the same laws of physics as any other engine.

 

[Wesley]

You may have a point.

 

[cmoneyr]

The treadmill is providing energy to the plane

Here is where your post falls apart. The treadmill is not providing any meaningful energy to the plane through the wheels. As we've been over a dozen times, the wheels on a plane are meant only to rotate to support the plane as it is pushed forward. The moving treadmill, and therefore the moving wheels do not transfer this energy to the plane. The jets of the plane aren't overcoming the treadmill, the treadmill means nothing.

The jet engines create thrust, and push the plane, on solid ground, the wheels only spin the same speed the plane is moving as a result of the thrust. Now add the treadmill, the wheels spin faster to accommodate for the ground which is now in motion, but since the wheels of a plane are not driving said plane and are instead just spinning freely, the plane does not jolt to a stop, it takes off as normal.

 

[cmoneyr]

Put an F-16 on its tail

I agree, you need sleep because that doesn't make any sense.

 

[singsing]

Here is where your post falls apart. The treadmill is not providing any meaningful energy to the plane through the wheels. As we've been over a dozen times, the wheels on a plane are meant only to rotate to support the plane as it is pushed forward. The moving treadmill, and therefore the moving wheels do not transfer this energy to the plane. The jets of the plane aren't overcoming the treadmill, the treadmill means nothing.

The jet engines create thrust, and push the plane, on solid ground, the wheels only spin the same speed the plane is moving as a result of the thrust. Now add the treadmill, the wheels spin faster to accommodate for the ground which is now in motion, but since the wheels of a plane are not driving said plane and are instead just spinning freely, the plane does not jolt to a stop, it takes off as normal.

You are correct.

 

[Warder60]

hehe, I posted this about 22 hrs ago, and it's on page 14 with about 200 replies ;P

Maybe after Wednesday a thread on this topic won't even make it past 1 pg. For those that don't check other forums, this topic gets mentioned in most forums, and usually has a response such as here =)