# A riddle

#### narcotic

##### Golden Member
There's an infinite rail road, and there's a cat that can run in an infinite speed.
A piece of metal is being attached to the cat's tail, so as the cat moves forward on the rail the metal thingy hits each one of the rail's bars and makes a *clang* noise. Now each time the cat hear *clang* it doubles its speed.
What would be the cat's final speed? And why...?

*Cat's initial speed is anything > 0

#### Lonyo

##### Lifer
-3mph.
Why? Because I didn't read the OP and put down a ranom number.

42

#### narcotic

##### Golden Member
Originally posted by: Lonyo
-3mph.
Why? Because I didn't read the OP and put down a ranom number.

close.. but no.

#### dawnbug

##### Golden Member
0? Because it would eventually run into a train?

Edit: Or whatever speed the train was going?

#### OdiN

##### Banned
This is a really stupid riddle.

#### imported_LoKe

##### Lifer
Does it have a final speed if the rail is infinite?

#### Auryg

##### Platinum Member
Uhh..infinity. It would keep on doubling forever.

Unless you mean speed of light - .00000000000000000000000001

#### narcotic

##### Golden Member
Originally posted by: OdiN
This is a really stupid riddle.

thnx.

#### narcotic

##### Golden Member
Originally posted by: LoKe
Does it have a final speed if the rail is infinite?

YES

#### Xionide

##### Diamond Member
Speed of sound. After the cat hit that it could no longer hear the clang and double its speed.

NEXT!

#### silverpig

##### Lifer
A little less than twice the speed of sound?

#### imported_LoKe

##### Lifer
Originally posted by: narcotic
Originally posted by: LoKe
Does it have a final speed if the rail is infinite?

YES

Then its final speed is zero, since the cat would undoubtedly die before completing his quest.

#### OdiN

##### Banned
Eventually the cat will be running at around 100MPH, which will have sufficient lift on the piece of metal to cause it to remain in midair and not clank anymore.

And at this time....the plane will take off.

#### narcotic

##### Golden Member
Originally posted by: Xionide
Speed of sound. After the cat hit that it could no longer hear the clang and double its speed.

NEXT!

FTW
care to explain...?

Edit: didn't see you explained that...

#### Xionide

##### Diamond Member
Originally posted by: narcotic
Originally posted by: Xionide
Speed of sound. After the cat hit that it could no longer hear the clang and double its speed.

NEXT!

FTW
care to explain...?

If you are traveling faster than sound than you are not going to be able to hear it.

#### imported_LoKe

##### Lifer
No. This riddle is flawed. The cat will have no final speed, for his run could never end.

#### silverpig

##### Lifer
Originally posted by: Xionide
Speed of sound. After the cat hit that it could no longer hear the clang and double its speed.

NEXT!

Say he's going at .9 times the speed of sound. He'll hear the clang, and jump up to 1.8 times the speed of sound.

#### OdiN

##### Banned
Originally posted by: narcotic
Originally posted by: Xionide
Speed of sound. After the cat hit that it could no longer hear the clang and double its speed.

NEXT!

FTW
care to explain...?

Edit: didn't see you explained that...

Not quite true.

If the cat was going at 99.9% of the speed of sound, then heard the clank, it would then double it's speed and be going much faster than the speed of sound.

So in order to solve the problem you need to be given a starting speed and a way to calculate how much time passes between each "clank", etc.

#### imported_LoKe

##### Lifer
Originally posted by: silverpig
Originally posted by: Xionide
Speed of sound. After the cat hit that it could no longer hear the clang and double its speed.

NEXT!

Say he's going at .9 times the speed of sound. He'll hear the clang, and jump up to 1.8 times the speed of sound.

:thumbsup:

This riddle loses.

#### silverpig

##### Lifer
Originally posted by: LoKe
Originally posted by: silverpig
Originally posted by: Xionide
Speed of sound. After the cat hit that it could no longer hear the clang and double its speed.

NEXT!

Say he's going at .9 times the speed of sound. He'll hear the clang, and jump up to 1.8 times the speed of sound.

:thumbsup:

This riddle loses.

The fastest the cat can go is a little under twice the speed of sound.

#### chuckywang

##### Lifer
The cat's final speed diverges linearly.

#### altonb1

##### Diamond Member
Originally posted by: LoKe
Originally posted by: silverpig
Originally posted by: Xionide
Speed of sound. After the cat hit that it could no longer hear the clang and double its speed.

NEXT!

Say he's going at .9 times the speed of sound. He'll hear the clang, and jump up to 1.8 times the speed of sound.

:thumbsup:

This riddle loses.

:thumbsdown: