# Simple U-Tube question

1. Sep 16, 2008

### Melawrghk

1. The problem statement, all variables and given/known data
A U-tube manometer contains a fluid with density of 825 kg/m^3. The difference in height of the two columns is 35cm. What is the pressure difference?

2. Relevant equations
None?

3. The attempt at a solution
I have no bloody clue. I'm sure I've done this before in AP Chem, but right now... I'm clueless. I think its something really simple, too.
Edit: Now that I think of it... the time variable in P=m/(A*t^2) doesn't change (there is no delta t), so density of the liquid multiplied by the difference in height squared would give me the difference in pressure. Am I even close to the truth?

Last edited: Sep 16, 2008
2. Sep 16, 2008

### mgb_phys

Pressure is force / area , or weight / area if you prefer.
You don't need the area of the tube since this cancels out, but if you prefer you can think of it as 1m^2.
Now just work out the weight of the extra 35cm * 1m^1 of fluid.
This is the weight pressing down on 1m^2 = pressure (watch the units)