Airplane on a treadmill

ddebened
Posers and Puzzles 22 Feb '08 21:42
1. 22 Feb '08 21:42
Consider a small airplane during take-off on a concrete runway. Just at take-off, it is traveling at 100 mph. That is the speed required to obtain sufficient lift for it to leave the ground.

Now, imagine this same plane is not on a concrete runway. Instead it is on a giant long treatmill. The surface of the treadmill is traveling at 100 mph in the opposite direction from the direction in which the plane is pointing. The plane's throttle is wide open just as it was on the concrete runway.

What will you observe in this case? Will the plane be able to take off? Why or why not.
2. Mexico
Quis custodiet
22 Feb '08 22:41
Originally posted by ddebened
Consider a small airplane during take-off on a concrete runway. Just at take-off, it is traveling at 100 mph. That is the speed required to obtain sufficient lift for it to leave the ground.

Now, imagine this same plane is not on a concrete runway. Instead it is on a giant long treatmill. The surface of the treadmill is traveling at 100 mph in the opposi ...[text shortened]... way.

What will you observe in this case? Will the plane be able to take off? Why or why not.
The plane will take off..... This has come up many many times already..... Planes derive their forward motion by pulling themselves through the Air, not down force on the wheels..... Thus the plane moves forward, thus there's air flow around the wings and the plane takes off.... and the wheels spin twice as fast......

Mythbusters actually proved this with a small ultralight aircraft.....
3. 22 Feb '08 22:48
I apologize for being repetitive. I have just now returned after a considerable absence from RHP and have not been following this forum.

Your statements are correct.
4. Mexico
Quis custodiet
23 Feb '08 01:30
Originally posted by ddebened
I apologize for being repetitive. I have just now returned after a considerable absence from RHP and have not been following this forum.

Your statements are correct.
Sorry if I came across as harsh also. Its just that this has been argued to death and I have a friend who still thinks it will only apply to smaller aircraft. That the down force on the wheels of say a 747 would be sufficient to prevent take off speeds.... I can't provide definite proof.... can any of you actually??
5. uzless
The So Fist
23 Feb '08 23:06
Originally posted by Mexico
Sorry if I came across as harsh also. Its just that this has been argued to death and I have a friend who still thinks it will only apply to smaller aircraft. That the down force on the wheels of say a 747 would be sufficient to prevent take off speeds.... I can't provide definite proof.... can any of you actually??
the thrust of the engines of a 747 can easily overcome the friction from the down force. As you said, the wheels will just spin faster.
6. Mexico
Quis custodiet
23 Feb '08 23:11
Originally posted by uzless
the thrust of the engines of a 747 can easily overcome the friction from the down force. As you said, the wheels will just spin faster.
Thats what I said, he just won't believe me.... I think I gonna need to get the exact specifications of a 747 and do the math just to prove the point....
7. uzless
The So Fist
23 Feb '08 23:22
Originally posted by Mexico
Thats what I said, he just won't believe me.... I think I gonna need to get the exact specifications of a 747 and do the math just to prove the point....
don't waste your time.....if he understands why a small plane can overcome the downforce but can't understand why a big plane can overcome the downforce, BECAUSE IT"S FRICKIN ENGINES ARE BIGGER, then your friend doesn't understand why a small plane can take off in the first place.

you'll just be banging your head for no reason.
8. Mexico
Quis custodiet
24 Feb '08 00:17
Originally posted by uzless
don't waste your time.....if he understands why a small plane can overcome the downforce but can't understand why a big plane can overcome the downforce, BECAUSE IT"S FRICKIN ENGINES ARE BIGGER, then your friend doesn't understand why a small plane can take off in the first place.

you'll just be banging your head for no reason.
I spend my life banging my head off the wall with this guy..... See I studied physics, and geology as well as bits of other sciences..... He did philosophy, English lit and politics..... But still has an opinion on everything....
9. edcburgos28
BORIQUA POWER
24 Feb '08 03:22
i neeed to know if there are any new peer 2peer sites available from anyone please
10. Mexico
Quis custodiet
24 Feb '08 03:32
Originally posted by edcburgos28
i neeed to know if there are any new peer 2peer sites available from anyone please
Use bit torrent and ISOhunt.com.... Peer to peer sucks, use torrents, faster safer and virus free generally...
11. 24 Feb '08 15:50
Originally posted by Mexico
Use bit torrent and ISOhunt.com.... Peer to peer sucks, use torrents, faster safer and virus free generally...
Err...BitTorrent is peer-to-peer.
12. agryson
AGW Hitman
24 Feb '08 18:19
Originally posted by Mexico
I spend my life banging my head off the wall with this guy..... See I studied physics, and geology as well as bits of other sciences..... He did philosophy, English lit and politics..... But still has an opinion on everything....
Tell him his opinion counts for \$h1t against fact. Done.
13. agryson
AGW Hitman
24 Feb '08 18:20
Originally posted by mtthw
Err...BitTorrent is peer-to-peer.
giggle. ðŸ˜µ
14. coquette
Already mated
24 Feb '08 21:55
Originally posted by Mexico
I spend my life banging my head off the wall with this guy..... See I studied physics, and geology as well as bits of other sciences..... He did philosophy, English lit and politics..... But still has an opinion on everything....
tell him that he is philosphically correct. the 747 can't take off because of all the angels sitting on the wings
15. Mexico
Quis custodiet
24 Feb '08 22:05
Originally posted by mtthw
Err...BitTorrent is peer-to-peer.
Sorry, i did know this, the point was its not peer to peer in the same way as other systems that are in common use..... Its very different.... If someone is asking about a new peer to peer system then chance are they're not using bittorrent anyway....

You did manage to make me look slightly stupid.... Well done ðŸ˜›