And lo On Sat, 31 Jul 2010 15:21:31 +0100, Orchid XP v8 <voi### [at] devnull>  
did spake thusly:

> According to the textbooks, it takes 1 Jule to move a 1 kg object a  
> distance of 1 meter.
>
> On the other hand, once the object has been moved, keeping it stationary  
> requires no energy at all. And, indeed, if you take a lump of metal and  
> put it on your bookshelf, it requires no energy to make it remain there.  
> It just sits there like a lifeless lump of metal.
>
> Now, here's the thing: How much energy does it take to hold a 1 kg lump  
> of metal at arm's legnth?
>
> According to physics, it would require 0 Jules. However, to keep the  
> object stationary against the force of gravity, the muscles in your arm  
> are having to continually expend chemical energy. But how the **** do  
> you compute how much energy that is??

To ask it another way how much energy is the bookshelf using to keep the  
lump of metal from falling through it under the influence of gravity ;-)

-- 
Phil Cook

--
I once tried to be apathetic, but I just couldn't be bothered
http://flipc.blogspot.com

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