Pressure as a function of depth

AI Thread Summary
The discussion revolves around calculating the density of oil in an oil-filled barometer, given that it is 80% filled and the height of a mercury barometer is 722 mm. The oil column height is determined to be 13.44 m, and participants clarify that the absolute pressure of the oil should equal that of the mercury for the calculation. The equation P=Po + pgh is referenced, with ambient pressure canceling out in the comparison. Participants confirm that the relevant height for the oil is 13.44 m, which is crucial for determining the density. The conversation highlights the importance of understanding the relationship between pressure, height, and density in fluid mechanics.
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1. There is a 16.8 m tall oil-filled barometer. The barometer column is 80.0% filled w/ oil when the column of a mercury barometer has a height of 722mm Hg. If the density of mercury is 1.36 x 10^4 kg/m^3, what is the density of oil?

Homework Equations


P=Po + pgh
D=m/v

The Attempt at a Solution



so the oil barometer has 13.44 m of oil. I know density of the mercury and the height of the mercury barometer. Do i have to set abs. pressure of oil to that of mercury and go from there? Any feedback would be appreciated.
 
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Is there a picture that goes along with this problem? Its worded in a way that confuses me (and you too, no doubt)?

Assuming the most straightforward situation,

Pa+Xrho*g*h=Pa+Hgrho*g*h. the Pa for ambient or atmospheric pressure cancel. G divides out. Does that help?
 
yeah it is worded a bit weird. Ok, so what's Xrho and Hgrho. Do u mean the density of the oil and mercury by that? And also for the depth of the oil, do i use 16.8 or 13.44 which is the height of the oil in the barometer?
 
Last edited:
yep I should bite the bullet and download Latex, but yes rho(density) for oil and Hg. And assuming these are separate physical systems, the height for oil would be 13.44
 
thx bro appreciate it.
 
No prob, keep coming back ;-D
 

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