# Problem with Pressure Equation units

I was doing a problem that required me to initially find the amount of pressure that was acting on a bubble, I decided that I had to use the equation P=P(STP) + ρgd. But looking at the equation, the units for the ρgd part of the problem doesn't make sense about how that gives me a unit of pressure (Pascal).

2. So I worked it out and:

ρ= kg/m^3
g= m/s^2
d= m

when multiplied together your units become kg/ms^2 which you are then adding to a pascal unit. So my question really is, is 1 kg/ms^2 = 1 Pa?

An explanation would be much appreciated!

SteamKing
Staff Emeritus
Homework Helper
I was doing a problem that required me to initially find the amount of pressure that was acting on a bubble, I decided that I had to use the equation P=P(STP) + ρgd. But looking at the equation, the units for the ρgd part of the problem doesn't make sense about how that gives me a unit of pressure (Pascal).

2. So I worked it out and:

ρ= kg/m^3
g= m/s^2
d= m

when multiplied together your units become kg/ms^2 which you are then adding to a pascal unit. So my question really is, is 1 kg/ms^2 = 1 Pa?

An explanation would be much appreciated!

1 Pascal = 1 Newton / m2

1 Newton = 1 kg-m/s2 [Using F = m a]

Therefore, 1 Pascal = 1 N / m2 = 1 kg m/s2 × (1/m2) = 1 kg / m-s2

Compare with the units arising from the product ρgd. Thank you so much! Makes sense now!