Cumulative General Science/Technology Quiz

[peter grimes]

Rat-a-tat, Nonconformist got it

These curious devices were not confined to the south coast of Britain, tho - they were also employed on the east coast.

I only learned of these last year, when a colleague of mine was married near one. I find it fascinating, this case of an acoustical-mechanical device being supplanted by an electro-magnetic device (radar).

Nonconformist is up!

 

[dutchfire]

I learned about them here: http://forums.civfanatics.com/showthread.php?t=229120&highlight=speed+sound&page=33 post #654 and onwards. (But the images are now gone )

 

[peter grimes]

If non-conformist isn't offering a question, the floor is open

 

[Brighteye]

Using average (or at least reasonable) values for the relevant figures, how long would it take someone to use all the oxygen in his lungs if he held his breath?

No, don't tell me he'd pass out before he managed it. Let's ignore that.

 

[Mise]

Are we allowed to look up the relevant figures, or do we have to guesstimate based on prior knowledge?

 

[Brighteye]

Well, it's basically asking you what average total lung volume is along with average O2 consumption. If you look them up then you only have some simple calculations to do.

So no, try to guess.

 

[StarWorms]

6 minutes? But I might be thinking of the capacity of the lung, which may be 6 litres.

Edit:

*Takes deep breath and duct tapes mouth*

 

[Ozbenno]

10 minutes?

 

[brennan]

If you metabolise some percentage of the oxygen each 'breath' -say 3 or 4 seconds- then the amount of oxygen used will decrease asymptotically towards zero.

 

[Brighteye]

6 minutes? But I might be thinking of the capacity of the lung, which may be 6 litres.

Edit:

*Takes deep breath and duct tapes mouth*

You win!
Average values are pretty much 6 litres for the lungs and 0.2 l/min O2 consumption. Since there's about 20% oxygen in the air, that's close to 6 minutes.

The world record is, apparently, over 8 minutes for a breath hold.

 

[brennan]

Surely your absorbtion of oxygen is related to the partial pressure though, which is going to drop significantly?

Crikey (did a quick google)

 

[Brighteye]

Only at very low partial pressures will it matter, and even then it's likely that there'll be oxygen transfer.
Diffusion across the lungs into the blood is not a rate-limiting process even at high altitude (at rest).

 

[StarWorms]

I can't think of a question right now, so the floor is open...

 

[Genocidicbunny]

Alright, a relatively simple question then: What is the triple point?

 

[ainwood]

Its a the temperature & pressure at which a pure substance exists in three states (solid, liquid, vapour).

 

[Genocidicbunny]

Its a the temperature & pressure at which a pure substance exists in three states (solid, liquid, vapour).

Dammit ainwood, you need to start giving other people a chance
I should also note, its where a substance exists in the 3 primary states in equilibrium. More info: Wiki

Oh yes, you're up ainwood.

 

[ainwood]

Thermodynamics questions I know.... Others I generally don't.

What is a wobbe index, what is it used for, and why is it important.

 

[Genocidicbunny]

Well damn, I know the answer to this one. Too bad I cant go as that would be against the rules.

 

[Rik Meleet]

I've heard the Wobbe index being used for gas for cooking. More details I do not have.

 

[aaglo]

It defines the direction of the movement of this:

EDIT: did I win? did I win? I surely must have...