# 1 Bar = ?

#### BMcN

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

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#### Ambitwistor

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

#### BMcN

Bit higher than I remember, but thanks!

#### chroot

Staff Emeritus
Gold Member
Re: Re: 1 Bar = ?

Originally posted by Ambitwistor
1 bar = 100,000 pascals = 100,000 kg/m/s2
Should be kg/m-s2

- Warren

#### Ambitwistor

Re: Re: Re: 1 Bar = ?

Either way works.

#### chroot

Staff Emeritus
Gold Member
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

#### Chi Meson

Homework Helper
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.

#### Njorl

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

Njorl

#### chroot

Staff Emeritus
Gold Member
Originally posted by Chi Meson
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.
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

#### Ambitwistor

So what is it in hpdpcf's (horsepower-decades per cubic furlong)?
1 bar = 3.4595574 hpdpcf's

#### Ambitwistor

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

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

You have: bar
* 3.4595574
/ 0.28905432

#### chroot

Staff Emeritus
Gold Member
You think you're better than me, punk?

- Warren

#### Chi Meson

Homework Helper
Originally posted by chroot
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
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.

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