# Unit conversion

1. Jan 3, 2017

### Minh Nguyen

1. The problem statement, all variables and given/known data
A mercury barometer located in a room at 25°C has a height of 750 mm. What is the atmospheric pressure in kPa?

2. Relevant equations
Patm = ρ*g*H0

3. The attempt at a solution

My question pertains to the units and how it ends up as kPa in the book. I have no problem with the calculations, just the unit conversion.

ρ*g*H0 = (13580 kg/m3) * (9.81 m/s2) * [ 750 mm * (1 m/1000 mm)]

= 99914.85 kg/s2*m ...... <--- is what I got.

The book got 99914.85 Pa which translates to 99.54 kPa.

Is kg/s2*m another way to say kPa?

2. Jan 3, 2017

### Staff: Mentor

Almost. $1\, Pa = 1\, \frac{kg}{ms^2}$ See here.