Pressure difference at same height in U-tube

[AmirWG]

my text box says that the pressure at point A is less than pressure at point B
Are not they supposed to have same pressure as they are on the same horizontal plane ?

 

[jbriggs444]

View attachment 239550
my text box says that the pressure at point A is less than pressure at point B
Are not they supposed to have same pressure as they are on the same horizontal plane ?

How does pressure change with height? Do you have a formula handy? One involving the fluid density, the acceleration of gravity and the height of a section of fluid, perhaps?

 

[Herman Trivilino]

Are not they supposed to have same pressure as they are on the same horizontal plane ?

Assuming the tubes are open to the atmosphere, the pressure at the top of each tube equals the pressure of the atmosphere. But note that the tops of the tubes are not at the same level? Evidently the two fluids in the tubes have different densities!

 

[AmirWG]

How does pressure change with height? Do you have a formula handy? One involving the fluid density, the acceleration of gravity and the height of a section of fluid, perhaps?

the only thing given is that the fluid in yellow is oil while the one in blue is water.

 

[AmirWG]

Assuming the tubes are open to the atmosphere, the pressure at the top of each tube equals the pressure of the atmosphere. But note that the tops of the tubes are not at the same level? Evidently the two fluids in the tubes have different densities!

so the pressure at point A is less than pressure at point B because the height at point B is greater than the height at point A ? right ?

 

[Herman Trivilino]

so the pressure at point A is less than pressure at point B because the height at point B is greater than the height at point A ? right ?

No. Points A and B are at the same height. Are you familiar with the expression $\rho gh$?