The case of the plane and conveyor belt - Page 2

daveake · 27 Oct 2007, 13:44

Actually, I'll have one more go. Imagine you're wearing roller skates. Imagine that you're at the start of a runway and you get one helluva kick up the backside. You're now doing 200mph down that runway. Do you stop immediately? Nope. You keep going. Eventually wind resistance slows you down and you might eventually come to a stop but probably not before you run out of runway.

Now imagine the same thing, but instead of you moving at 200mph, you're stationary on a conveyor that happens to be moving 200mph backwards. You'll start moving backwards, but only a little (unless you bought very cheap roller skates). If the belt is really really long you'll eventually get thrown off fairly quickly to an untimely death, but the point is that you don't suddenly get chucked backwards at 200mph. You get saved by the wheels on those skates, which spin away like bug-gery.

Having survived that experience, you metamorphosis into a big jet plane. The belt starts moving, and you feel a little tug on your wheels. But you've got some BFO jet engines which are much more powerful. So you turn those on and easily overcome the resistance of the wheels. You roll forwards, and then take off to that holiday in the Galapagos that you've been saving up for.

The actual scenario in the root message was easier to overcome - the belt only starts moving backward when the plane moves forward. The trick though is that it starts making people think that the plane can't take off because the belt matches the plane's speed, like a belt down at the gym. Fortunately planes have unpowered wheels and not legs.

Dave

**Monstro** · 27 Oct 2007, 14:04

Can everyone see the lightbulb go on above my head?

Cheers Dave

duke knooby · 27 Oct 2007, 14:05

"we have lift off" lol

needmoremeat · 02 Nov 2007, 12:53

So, could that be the solution to mega long runways for the A380?

tukayaway · 04 Nov 2007, 14:55

Quote:

Originally Posted by needmoremeat

So, could that be the solution to mega long runways for the A380?

I would patent that idea!

daveake · 24 Nov 2008, 10:40

(Holy Thread Resurrection, Batman!) ...

And here's the result from those Mythbusters guys.

YouTube Video

~Helen~ · 24 Nov 2008, 19:34

I didn't spot this first time it was posted, think it's a cool conundrum, and am now going to irritate everyone I know with the question!

mszee · 24 Nov 2008, 21:00

Yeah, I skipped over this one cause R. usually posts videos which I can't watch at work. However, then I missed it from home too...nothing much to say but I amazed myself by actually understanding what Dave said first time around...on the other hand...he started to scare me even MORE...

**RadioMaster** · 24 Nov 2008, 21:01

dave can be quite scary, especially when hes driving

mszee · 24 Nov 2008, 21:06

Quote:

Originally Posted by RadioMaster

dave can be quite scary, especially when hes driving

You didn't get into the car he was driving, did you???

samurai7 · 24 Nov 2008, 21:13

Quote:

Originally Posted by RadioMaster

dave can be quite scary, especially when hes driving

Try being in Hennie's car next time then. He thought he was Michael Schumacher!

daveake · 24 Nov 2008, 21:26

Quote:

Originally Posted by mszee

You didn't get into the car he was driving, did you???

Why not? It's the best way to avoid being run over

Dave

daveake · 24 Nov 2008, 21:28

Quote:

Originally Posted by samurai7

Try being in Hennie's car next time then. He thought he was Michael Schumacher!

What, you mean desparately trying to keep up with the English guy in front?

Dave

mszee · 24 Nov 2008, 21:34

Quote:

Originally Posted by daveake

Why not? It's the best way to avoid being run over

Dave

Good argument, very eloquently presented...

**Monstro** · 26 Nov 2008, 05:11

I did eventually figure this out lol

27 Oct 2007, 13:44	#26
daveake 200% is the new 110% Join Date: 13.03.2005 Location: Newbury Posts: 2,983	Actually, I'll have one more go. Imagine you're wearing roller skates. Imagine that you're at the start of a runway and you get one helluva kick up the backside. You're now doing 200mph down that runway. Do you stop immediately? Nope. You keep going. Eventually wind resistance slows you down and you might eventually come to a stop but probably not before you run out of runway. Now imagine the same thing, but instead of you moving at 200mph, you're stationary on a conveyor that happens to be moving 200mph backwards. You'll start moving backwards, but only a little (unless you bought very cheap roller skates). If the belt is really really long you'll eventually get thrown off fairly quickly to an untimely death, but the point is that you don't suddenly get chucked backwards at 200mph. You get saved by the wheels on those skates, which spin away like bug-gery. Having survived that experience, you metamorphosis into a big jet plane. The belt starts moving, and you feel a little tug on your wheels. But you've got some BFO jet engines which are much more powerful. So you turn those on and easily overcome the resistance of the wheels. You roll forwards, and then take off to that holiday in the Galapagos that you've been saving up for. The actual scenario in the root message was easier to overcome - the belt only starts moving backward when the plane moves forward. The trick though is that it starts making people think that the plane can't take off because the belt matches the plane's speed, like a belt down at the gym. Fortunately planes have unpowered wheels and not legs. Dave

27 Oct 2007, 14:04	#27
Monstro Promoted to Wario's spellchecker Join Date: 17.09.2005 Location: London Posts: 12,946	Can everyone see the lightbulb go on above my head? Cheers Dave

27 Oct 2007, 14:05	#28
duke knooby Mega Loafer Join Date: 24.06.2005 Location: belfast Posts: 17,884	"we have lift off" lol

02 Nov 2007, 12:53	#29
needmoremeat Mega Loafer Join Date: 23.11.2003 Location: Sunderland, UK Posts: 1,416	So, could that be the solution to mega long runways for the A380?

24 Nov 2008, 19:34	#32
~Helen~ Mega Loafer Join Date: 01.11.2007 Location: Manchester Posts: 1,958	I didn't spot this first time it was posted, think it's a cool conundrum, and am now going to irritate everyone I know with the question!

24 Nov 2008, 21:00	#33
mszee Mega Loafer Join Date: 29.03.2006 Location: And you think you're down under??? Posts: 26,252	Yeah, I skipped over this one cause R. usually posts videos which I can't watch at work. However, then I missed it from home too...nothing much to say but I amazed myself by actually understanding what Dave said first time around...on the other hand...he started to scare me even MORE...

24 Nov 2008, 21:01	#34
RadioMaster The German Join Date: 11.03.2006 Location: some kind of hunting lodge for rich weirdos... Posts: 15,778	dave can be quite scary, especially when hes driving

26 Nov 2008, 05:11	#40
Monstro Promoted to Wario's spellchecker Join Date: 17.09.2005 Location: London Posts: 12,946	I did eventually figure this out lol