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>>> Estimate the mass of air in this room.
>>
>> 3 grams?
>
> Estimate, not guess!
Well, with no actual data to estimate with, it's kinda hard. :-P
> You'll never make an Engineer if you can't tell
> when your calculations are off by several orders of magnitude.
Heh. Well, I have no idea what the volume of this room is. I don't even
"really" know how big a meter is. It used to be the length of my arms,
but they're a tad bigger now. ;-)
> BTW a
> cubic metre of air is about 1kg, so you must be in a very small room.
Really? I was under the impression that all gasses are absurdly light.
(E.g., off the top of my head Oxygen is supposed to be something silly
like 0.000004 g per cubic meter or something.)
> I think it's safe to assume the external temperature is lower than the
> internals of the bird, but anyway the point of this one was that for
> cylinders below a certain radius lagging them actually makes them
> release more heat rather than less, because the surface area increase
> has more affect than the lagging. Useful to know if you ever think
> about insulating thin pipes :-)
Now, see, I was under the impression that lagging traps air, and hence
the "effective" surface area would still be the same.
>> ...oh, wait, maybe you meant the *graph* of this?
>
> Har har.
Aww, c'mon! I thought that was a really neat drawing! :-D
>> Hmm. Well two cubed is 8, while three squared is 9, so I'm going to go
>> with pi^e being larger.
>
> Wrong!
>
>> Presumably "proving" this would simply involve slightly more
>> arithmetic. :-P
>
> http://mathforum.org/library/drmath/view/53916.html
...OK, I am now completely bemused. Apparently e^3 is roughly 20. I
cannot work out how that can possibly be. 2^3 is clearly 8. My head
hurts just thinking about it.
As an aside, I notice the difference turns out to be especially tiny. :-P
>> I don't know why it took me so long; it's really quite
>> simple when you look at it. I think I just confused myself too much to
>> see it...
>
> That was the story of my whole thermodynamics course at university!
I think you need... THERMITE!! 8^D
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