Pressure in a Rectangular Tank

[uno]

1. A rectangular tank 2.0 m by 2.0 m by 3.5 m high contains gasoline, with a density of 0.68E3 kg/m3, to a depth of 2.5 m. What is the gauge pressure anywhere 1.2 m below the surface of the gasoline?



2. P=Ps + Pl Pl=density (g) (h)



3. I'm sure this is an easy problem, but I don't know where I am going wrong. I set Ps to atmospheric pressure at 1.013 E5 and Pl = .68 E3 (9.81) (2.5). I added Ps and Pl together to get 1.18 E5, but this is incorrect. Please help out if you can. Thanks.

 

[uno]

I found a new formula. P = Pa + Pg. My question is: when I use P= density x gravity x height, what value do I enter for the height? 3.5 or 2.5? Thanks

 

[Doc Al]

My question is: when I use P= density x gravity x height, what value do I enter for the height? 3.5 or 2.5?

Neither. You'd use the depth below the surface of the fluid. (That formula gives the pressure due to the weight of the fluid, which in this case is the gauge pressure.)