A brainteaser.. The Airline Short Takeoff Conveyor.

Here's something that startled me... heard it on the radio, guy arguing about the results of:

What will happen?

I think it's funny that the guy on the radio is a pilot, and he got it wrong. I'm not, and I got it right.

Take the poll and tell why.
- - - -- - - - -- - - - - - -
Added:
If you really understand what you learned about how planes fly in middle school science class, you'll get it right.

Poll set up to close 5 days from time I posted it!

 

planes need a forward velocity to create a downforce on the wings to create lift?

 

If the conveyor runway doesnt allow the plane to move than that plane is never actually traveling, not building speed, and cannot create proper amount of wind friction it would need to take off...

I wonder... would the time machine from Back to the Future suffer the same fate.

 

except the plane won't get thinner!!

....nope, velocity and speed are 2 different things

 

i'm assuming it's the first one seeing as everyone (including petty) voted, and he admitted that he got it right even though he's not a pilot

 

i did not vote

and the poll expires in 4 days

 

And, remember, laws of physics do notrespond to a democratic vote.

 

Maybe I'm a numpty cuz I have no idea what that is.

 

Term of endearment? Are you flirting with me?

 

numpty = muppet!!

i just knew the answer because i spend half my life on a plane taking off, then landing, then taking off, the landing again, then some more taking off......

 

I was the first to vote...but I didn't leave comment as to why.

but i agree with misswitch2 and smokin' where the plane needs to move forward to create downforce.

If it was possible for a plane to take off from a conveyour belt (not having to move forward to take off) I would think the Navy would have been all over this years ago on their aircraft carriers.

 

Due to popular demand {no one else gives a s__t!}, I'm gonna end this early!

Bear in mind:

The conveyor has little to no effect on air surrounding it. Yes, there IS a 'skin effect', but let's not quibble.

Aircraft gets lift from air passing over its wing

Force from engines operates on "equal and opposite reaction", not applied against the conveyor.

Actual speed of aircraft has nothing to do with how fast its wheels are turning

If the aircraft is sitting still, relative to surroundings, then the conveyor would be still, also.

So, the correct answer is:

Minor friction increases aside, the aircraft takes off in same distance as it would without conveyor.

Only difference is the wheels are turning twice as fast at lift-off as they would if the runway were concrete and not moving.

Like I said, dont feel bad... the radio host/ licensed pilot thought the plane would be sitting still also. He, quite churlishly, said "Enough of the conveyor emails, already!"
The original poster:
http://www.avweb.com/news/columns/191034-1.html

Added:

While I got THAT right.. I have an engineering bent... I would have gotten the 'downwind leg' puzzle wrong. After all, I'm NOT a pilot.

Though it worries me that a pilot MIGHT have got it wrong.

 

UPDATE, kids.....

You are not alone!

http://www.thetechlounge.com/forum/show ... ge=1&pp=10

Now I am worried... either about the state of learning in our public schools... or that I'm too dumb to be fooled!