Warp <war### [at] tagpovrayorg> writes:

> scott <sco### [at] scottcom> wrote:
>> >> it's also useful that 1 bar ~= 10 metres of water for quick estimations.
>> >
>> >  I didn't quite understand that.
>
>> It's useful for quick estimations involving water (one of the most common 
>> pressurised fluids you come across) because it's a multiple of 10.
>
>> eg a water tank 4 metres above the tap, pressure at the tap is 0.4 bar.
>
>> or, 2 bar coming into your house, what's the pressure at the valve in your 
>> roof 6 metres up?  1.4 bar
>
>   You mean that when you dive, each 10 meters of depth adds approximately
> 1 bar of pressure?

Yep. Pressure in a liquid is h*g*density (g being 9.8 m/s^2 in most
places). 

Since water has a nice density, it works out approximately (take g to be
10).

Post a reply to this message