# 1 Bar = ?

1. ### BMcN

11
What the conversion for bar so that I can use it to work out volume and temprature? Whats the units?

2. ### Ambitwistor

837
1 bar = 100,000 pascals = 100,000 kg/m/s2

3. ### BMcN

11
Bit higher than I remember, but thanks!

4. ### chroot

10,426
Staff Emeritus
Re: Re: 1 Bar = ?

Should be kg/m-s2

- Warren

5. ### Ambitwistor

837
Re: Re: Re: 1 Bar = ?

Either way works.

6. ### chroot

10,426
Staff Emeritus
Not to be a pain in the ass, but I'd normally think

kg/m/s^2 = kg s^2 / m

But I guess it does come down to the conventional order of operations. I guess you win. Gack. I personally hate when people describe accelerations as "meters per second per second" i.e. m/s/s, for the same reason.

- Warren

7. ### Chi Meson

1,772
Interesting note:

In the "common" world, a bar has the unit "kg/cm^2". THis is referring to the weight of one kilogram per square centimeter. THis of course translates to only 98,010 N per square meter, but somewhere along the line, "g" got upgraded to 10 N/kg instead of 9.801 N/kg.

8. ### Njorl

875
So what is it in hpdpcf's (horsepower-decades per cubic furlong)?

Njorl

9. ### chroot

10,426
Staff Emeritus
Uh.... no.

1 bar is defined to be 100 kilopascals. A pascal is one newton per square meter. One kilogram-force is g newtons. Therefore, one pascal is (1/g) kilogram-force per square meter. Therefore, one bar is 100,000/g kilograms-force per square meter.

g is accepted to be 9.80665 m/s^2, so one bar is 10,197.1621298 kilograms-force per square meter.

I have no idea where you got the idea that someone rounded g to 10 m/s^2, but it never happened.

- Warren

10. ### Ambitwistor

837
1 bar = 3.4595574 hpdpcf's

11. ### chroot

10,426
Staff Emeritus
12. ### Ambitwistor

837
I used the Unix 'units' program, since I had a shell already open ...

Code (Text):

\$ units
2084 units, 71 prefixes, 32 nonlinear units

You have: bar
* 3.4595574
/ 0.28905432

13. ### chroot

10,426
Staff Emeritus
You think you're better than me, punk?

- Warren

14. ### Chi Meson

1,772
That's not what I meant, really. In Europe, the unit of bar and kg/cm^2 is used interchangeably (not by scientists, but by people pumping their bike tires). I remember several times over the years hearing anecdotaly that the bar was based on the "kg/cm^2" but was then redefined to be essentially 10 N/cm^2 (actually 1,000,000 dynes per cm^2)to be scientifically correct.

So g was not the one that was adjusted. It's the bar that was raised.