Mechanical Engineering Riddle

[kdogg]

TweetIf you have an infinitely long metal chain and an infinitely deep hole how much chain can you lower down into the hole?

-kdog

[Testify]

TweetAll of it.

[kdogg]

TweetI'm sorry but that answer is incorrect.

I'll wait for a couple more responses before I post the answer.

-kdog

[Testify]

TweetOK, if its infinitely long then you'll never finish lowering it into the whole. So, the answer cannot be "all of it." Hypothetically, you could fit all of it, but you'd never get to that point. Hmmm . . .

[Testify]

TweetI know, assuming we are on the planet earth . . . 9.8m/s/s ?

[supasaiyan99]

TweetDamn it!!! I don't know that one. My educated guess is one. infinity/infinitiy = 1

[O2BESOHUGE]

TweetCOM ON KDOGG...WHAT IS IT?

[Evil Ryu]

Tweetan infinite amount

[kdogg]

TweetWell, if the material used to make the chain is infiitetly strong you could lower an infiinite amount of chain into the hole.

However, since chain is made from metal (steel) it has a finite tensile strength. Therefore, the amount of chain that can be lowered into the hole would depend on the amount of chain (which has weight) that would cause a link (at lowering point) to break due to tensile stress.

So when gravity acts upon the chain and causes a downward force that exceeds the strength of the chain link it will cause it to break.

Don't worry this one stumped me too when my boss asked me.

-kdog

[Gooseneck]

Tweet****, thats the first thing I thought of, tensile strength. No I'm not bull****tin either.

[supasaiyan99]

Tweet

Well, if the material used to make the chain is infiitetly strong you could lower an infiinite amount of chain into the hole.

However, since chain is made from metal (steel) it has a finite tensile strength. Therefore, the amount of chain that can be lowered into the hole would depend on the amount of chain (which has weight) that would cause a link (at lowering point) to break due to tensile stress.

So when gravity acts upon the chain and causes a downward force that exceeds the strength of the chain link it will cause it to break.

Don't worry this one stumped me too when my boss asked me.

-kdog

Awesome!

[Testify]

TweetWhat if it is on a frictionless spool positioned directly over the hole? Then I would be right!

Wouldn't I? Hmmm . . .

[kdogg]

TweetTestify,

In this case friction does not come into play. What is important is the point at which it is being lowered. All the chain below this point has a weight which, along with gravity, will cause a force to act on the link that is being held and lowered at that moment.

When the force caused by the weight of the chain exceeds the ultimate tensile strength of the link that is being held and lowered it will cause it the link to fail.

-kdog

[Testify]

TweetTrue, but hypothetically, if the chain is positioned on a frictionless spool, then it's velocity can accelerate to maximum velocity, without concern to tensile strenght. There would be not weight borne by the individual links if it flowed freely without resistance.

At least, that's what I was thinking - but I'm not an engineer. I only took an AP Physics calss back in HS. I just thought I was smart for a second. Humor me.

[SpyWizard]

Tweethow big around is the hole??/

you didn't say anything about volume, or distance.. .