# Pressure/Fluid Concepts

## Homework Statement

so i just had some questions:
1. is there a difference between h and d?
sometimes i see P = $$\rho$$gh and other times P = $$\rho$$gd
is there a difference? because if d=depth while h=height, would d always be a neg number?

2. for hydrostatic pressure, i was taught: P = Patm + $$\rho$$gd, but i notice when I look at other's questions they will leave out the atmospheric pressure. Is there a difference? why do they leave it out?

3. Is there some kind of "steps" i can follow when assessing a pressure/fluid problem to decide what method to use to solve it?
for example, if it is a U-tube problem, look to use the concept that at the same level pressure is equal in the two arms so P1 = P2....

## Homework Statement

so i just had some questions:
1. is there a difference between h and d?
sometimes i see P = $$\rho$$gh and other times P = $$\rho$$gd
is there a difference? because if d=depth while h=height, would d always be a neg number?

2. for hydrostatic pressure, i was taught: P = Patm + $$\rho$$gd, but i notice when I look at other's questions they will leave out the atmospheric pressure. Is there a difference? why do they leave it out?

3. Is there some kind of "steps" i can follow when assessing a pressure/fluid problem to decide what method to use to solve it?
for example, if it is a U-tube problem, look to use the concept that at the same level pressure is equal in the two arms so P1 = P2....