View Poll Results: what do you think?
Hoss is da man, no
25
33.78%
Geico's question. He knows, yes
42
56.76%
your both wrong its a vto
7
9.46%
Voters: 74. You may not vote on this poll
will the plane fly?
Thread Starter
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Joined: Mar 2004
Posts: 3,988
Likes: 7
From: Nebraska
Originally Posted by rac156
Ok, so the wheels make 100 revolutions/min . The wheel travels 10 ft per revolution so the forward velocity is 100 rev/min * 10ft/rev =1000 ft/min
in one min the wheel will travel 1000ft/min *1min= 1000ft.
the conveyor matches the speed of the wheel which is 1000ft/min
so in 1 min the conveyor has traveled 1000ft/min *1 min = 1000 ft/min
In order for the plane to take off the plane must travel faster than the conveyor. In other words it must travel a greater distance in the same amount of time. So lets say the plane is going 1100 ft/min
in the same min that the wheel traveled 1000 ft the plane will travel 1100 ft/min *1 min = 1100 ft.
In other words the plane is now 100 ft in front of its own wheels!
Someone explain to me how this can happen.
in one min the wheel will travel 1000ft/min *1min= 1000ft.
the conveyor matches the speed of the wheel which is 1000ft/min
so in 1 min the conveyor has traveled 1000ft/min *1 min = 1000 ft/min
In order for the plane to take off the plane must travel faster than the conveyor. In other words it must travel a greater distance in the same amount of time. So lets say the plane is going 1100 ft/min
in the same min that the wheel traveled 1000 ft the plane will travel 1100 ft/min *1 min = 1100 ft.
In other words the plane is now 100 ft in front of its own wheels!
Someone explain to me how this can happen.
Registered User
Joined: Nov 2005
Posts: 0
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From: Iowa
tied to the thrust or not, you agree they have to turn at the forward speed of the plane + the speed of the conveyor correct?
I think the key to the brain teaser is that people think it matters whether the wheels are driven or not.
I think the key to the brain teaser is that people think it matters whether the wheels are driven or not.
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Joined: Nov 2002
Posts: 1,234
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From: outside of Duluth MN
Of course the plane has to move faster than the conveyor. It has to travel at twice the speed!! As it was stated in the article, the tires are just FREEWHEELING. Therefore, the speed of the conveyor is a moot point. The plane will become airborn.
Thread Starter
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Joined: Mar 2004
Posts: 3,988
Likes: 7
From: Nebraska
Originally Posted by MnTom
Of course the plane has to move faster than the conveyor. It has to travel at twice the speed!! As it was stated in the article, the tires are just FREEWHEELING. Therefore, the speed of the conveyor is a moot point. The plane will become airborn.
http://www.cirrusdesign.com/
Registered User
Joined: Nov 2002
Posts: 1,234
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From: outside of Duluth MN
Originally Posted by Geico266
Duluth, MN Home of Cirrus. The best single engine airplane built today.
http://www.cirrusdesign.com/
http://www.cirrusdesign.com/
Registered User
Joined: Sep 2005
Posts: 12
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From: Ft. Rucker, AL and Savannah, GA
Originally Posted by oscaroc
...And Jr is going to be spending the week in the dog house 
this whole debate is why I fly helos, we just beat the air into submission
Registered User
Joined: Jan 2005
Posts: 191
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From: The Rock
Ok...A Harrior jump jet. Points the engines down, lifts off of the conveyor belt, adjusts attack angle of engines to begin moving forward and wala. Jet engines, tires touching conveyor belt to begin with, plane takes off.
I WIN
I WIN
Registered User
Joined: Nov 2001
Posts: 3,733
Likes: 264
From: Austria Europe
It may seem illogical, but....
Let's take our plane and place it on the conveyor belt. As soon as we try to move the plane relatively to the ground outside the conveyor belt we do have ground speed and wheel speed (and air speed). But now comes the moment our conveyor belt will start to move. (Let's say we caught the belt by surprise and moved the plane 1 mm in the first second) - Since the belt will match wheelspeed it will move the wheel 1 more mm per second- now the wheel has moved 2mm in the 2nd second , the belt adds another 2mm etc- this row will go towards infinite speed in zero time.(for units of time that are infinite fractions of seconds) Infinite speed would mean infinite friction of the wheels, so the prop/jet engine with finite power won't overcome it.
The belt and the wheels will go up to infinite speed without the plane moving.
AlpineRAM
Let's take our plane and place it on the conveyor belt. As soon as we try to move the plane relatively to the ground outside the conveyor belt we do have ground speed and wheel speed (and air speed). But now comes the moment our conveyor belt will start to move. (Let's say we caught the belt by surprise and moved the plane 1 mm in the first second) - Since the belt will match wheelspeed it will move the wheel 1 more mm per second- now the wheel has moved 2mm in the 2nd second , the belt adds another 2mm etc- this row will go towards infinite speed in zero time.(for units of time that are infinite fractions of seconds) Infinite speed would mean infinite friction of the wheels, so the prop/jet engine with finite power won't overcome it.
The belt and the wheels will go up to infinite speed without the plane moving.
AlpineRAM
Thread Starter
Registered User
Joined: Mar 2004
Posts: 3,988
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From: Nebraska
Originally Posted by AlpineRAM
It may seem illogical, but....
Let's take our plane and place it on the conveyor belt. As soon as we try to move the plane relatively to the ground outside the conveyor belt we do have ground speed and wheel speed (and air speed). But now comes the moment our conveyor belt will start to move. (Let's say we caught the belt by surprise and moved the plane 1 mm in the first second) - Since the belt will match wheelspeed it will move the wheel 1 more mm per second- now the wheel has moved 2mm in the 2nd second , the belt adds another 2mm etc- this row will go towards infinite speed in zero time.(for units of time that are infinite fractions of seconds) Infinite speed would mean infinite friction of the wheels, so the prop/jet engine with finite power won't overcome it.
The belt and the wheels will go up to infinite speed without the plane moving.
AlpineRAM
Let's take our plane and place it on the conveyor belt. As soon as we try to move the plane relatively to the ground outside the conveyor belt we do have ground speed and wheel speed (and air speed). But now comes the moment our conveyor belt will start to move. (Let's say we caught the belt by surprise and moved the plane 1 mm in the first second) - Since the belt will match wheelspeed it will move the wheel 1 more mm per second- now the wheel has moved 2mm in the 2nd second , the belt adds another 2mm etc- this row will go towards infinite speed in zero time.(for units of time that are infinite fractions of seconds) Infinite speed would mean infinite friction of the wheels, so the prop/jet engine with finite power won't overcome it.
The belt and the wheels will go up to infinite speed without the plane moving.
AlpineRAM
Another way to look at it is; the wheels are free rolling, the aircraft is disconnected from any ground influences. (so to speak...) Two aircraft side by side. One on the treadmill scenario and the other on a regular tarmac. Both would accelerate and take off side by side. How fast the wheels are turning wouldn’t matter. Assuming friction is not in the equation the planes would actually take off at the same time.
Thats MR Hoss to you buddy!
Joined: Jul 2001
Posts: 2,759
Likes: 3
From: Central Texas
Originally Posted by MnTom
Of course the plane has to move faster than the conveyor. It has to travel at twice the speed!!
THAT, gentlemen, is the REAL answer to this little puzzle.
Thats MR Hoss to you buddy!
Joined: Jul 2001
Posts: 2,759
Likes: 3
From: Central Texas
Originally Posted by AlpineRAM
It may seem illogical, but....
Let's take our plane and place it on the conveyor belt. As soon as we try to move the plane relatively to the ground outside the conveyor belt we do have ground speed and wheel speed (and air speed). But now comes the moment our conveyor belt will start to move. (Let's say we caught the belt by surprise and moved the plane 1 mm in the first second) - Since the belt will match wheelspeed it will move the wheel 1 more mm per second- now the wheel has moved 2mm in the 2nd second , the belt adds another 2mm etc- this row will go towards infinite speed in zero time.(for units of time that are infinite fractions of seconds) Infinite speed would mean infinite friction of the wheels, so the prop/jet engine with finite power won't overcome it.
The belt and the wheels will go up to infinite speed without the plane moving.
AlpineRAM
Let's take our plane and place it on the conveyor belt. As soon as we try to move the plane relatively to the ground outside the conveyor belt we do have ground speed and wheel speed (and air speed). But now comes the moment our conveyor belt will start to move. (Let's say we caught the belt by surprise and moved the plane 1 mm in the first second) - Since the belt will match wheelspeed it will move the wheel 1 more mm per second- now the wheel has moved 2mm in the 2nd second , the belt adds another 2mm etc- this row will go towards infinite speed in zero time.(for units of time that are infinite fractions of seconds) Infinite speed would mean infinite friction of the wheels, so the prop/jet engine with finite power won't overcome it.
The belt and the wheels will go up to infinite speed without the plane moving.
AlpineRAM
HA!! Another NO FLY man!!! Looks like we win!!!!
Thats MR Hoss to you buddy!
Joined: Jul 2001
Posts: 2,759
Likes: 3
From: Central Texas
Originally Posted by John Rodriguez
I know how to solve this once and for all. I'll strap a rocket engine to a skate, and ignite it at the same time I put the treadmill on high.