Earth spinning

Tefal · 8 Jun 2010 at 18:43

So how many sandwiches are there?

neodude · 8 Jun 2010 at 18:49

Tefal said:
So how many sandwiches are there?

5, if you take air friction out of the equation!

Beren · 8 Jun 2010 at 18:50

Tefal said:
So how many sandwiches are there?

One If you aint a ponce.

Swifty55 · 8 Jun 2010 at 19:03

Beren said:
One If you aint a ponce.

No, it's 2...

Dark_Angel · 8 Jun 2010 at 19:03

Tefal said:
So how many sandwiches are there?

Over 9000.

Dano · 8 Jun 2010 at 19:10

Beren said:
Holy cataclysmic event Batman! He asked a question that Broke the Laws Of Physics!

Sigh...

Sorry your semantics failed

No, they didn't.

Sorry couldn't help it - your quote belongs somewhere in the Hitch Hikers Guide along the lines of what happens when the Question and Answer appear simultaneaously.

No, it doesn't, you've just failed to understand the point, much like neodude keeps doing.

neodude · 8 Jun 2010 at 19:17

Here we go again....

What point exactly am I missing?

Dano · 8 Jun 2010 at 19:18

neodude said:
Here we go again....

What point exactly am I missing?

This one:

Either the laws of physics apply in which case it'll take off or they don't and it can do whatever the hell anybody cares to think of including turning into a bright pink four hundred storey elephant with a penchant for flip flops.

lee32uk · 8 Jun 2010 at 19:36

Malt_Vinegar said:
Please don't start that one!

Yes, it will fly... Please no one else suggest anything else!

What if it didn't have any engines ?

Lightnix · 8 Jun 2010 at 19:40

lee32uk said:
What if it didn't have any engines ?

Then the passengers all get very bored and the crew members go on strike.

neodude · 8 Jun 2010 at 19:48

Dano said:
This one:

That point is irrelevant. I was merely answering the question.

Dano · 8 Jun 2010 at 19:52

lmao.

arknor · 8 Jun 2010 at 19:59

Swifty55 said:
No, it's 2...

yea 2 halves of 1 sandwhich unless you cut your loaf diagonally and call it twice as many slices

arknor · 8 Jun 2010 at 19:59

Swifty55 said:
No, it's 2...

yea 2 halves of 1 sandwhich unless you cut your loaf diagonally and call it twice as many slices.

i go buy a pizza its cut into 8 slices i dont call it 8 pizzas

>FAIL EDIT!<

Dark_Angel · 8 Jun 2010 at 20:13

"Either the laws of physics apply in which case it'll take off or they don't and it can do whatever the hell anybody cares to think of including turning into a bright pink four hundred storey elephant with a penchant for flip flops. "

So. Much. Win.

Haircut · 8 Jun 2010 at 20:18

0.999... recurring is not equal to 1

/runs

Fuzz · 8 Jun 2010 at 20:19

neodude said:
The second version of the question stated that the treadmill matches the wheelspeed of the plane. In this case it is impossible for the plane to move. In order for the plane to move the wheels must be moving at a different speed to the treadmill,

LOL I really can't be arsed to get into this but have a word with yourself.

Its got absolutely NOTHING to do with wheel speed.
You could put the plane on skids for all it matters.
IF the engine thrust is greater than the friction of skids/wheels/whatever..
The plane will move through the AIR.
When air speed is greater than the weight of the aircraft due to lift created over the wings.. THE PLANE TAKES OFF.

How can people not see this.. <mind boggle>

Inquisitor · 8 Jun 2010 at 20:24

Edit: brainfart.

"andy" · 8 Jun 2010 at 20:28

Scubascorpion said:
LOL I really can't be arsed to get into this but have a word with yourself.

Its got absolutely NOTHING to do with wheel speed.
You could put the plane on skids for all it matters.
IF the engine thrust is greater than the friction of skids/wheels/whatever..
The plane will move through the AIR.
When air speed is greater than the weight of the aircraft due to lift created over the wings.. THE PLANE TAKES OFF.

How can people not see this.. <mind boggle>

dont bother mate. really just dont

lord filbuster · 8 Jun 2010 at 20:33

Inquisitor said:
That formulation of the question doesn't make sense, so any "answer" to it is invalid.

Assuming the "speeds" of both the conveyor belt (say v) and the wheels (say u) are being measured relative to the ground, then the former will always be twice the latter, i.e. u = 2v. Hence, from the problem statement:

u = v
∴ 2v = v
∴ v = 0

Hence, the only scenario in which the problem statement is mathematically consistent (let alone physically possible) is when the conveyor belt is stationary.

So if you place a toy car on a treadmill, and prevent it from moving by placing your finger behind it, the wheels must be moving twice as fast as the treadmill belt?