An oil filled system- finding d

[tensor0910]

Homework Statement

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An oil filled system is shown in the figure below. The density of the oil is

.

In the figure(Figure 1)how much force does the fluid exert on the end of the cylinder at A?

Homework Equations

The Attempt at a Solution

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Solved for P_oil using P = P_o + F/A = 1.79 X 10⁵. Simple enough.

Since pressure is the same across any level, we first have to first figure out the distance from P_o to the top of A. This is where I am stuck. I feel like its something very simple but I just don't see it!

Spoiler

The distance is 70cm. We did this one in class, but I still don't see it.

 

[Bystander]

You have to make an assumption based on the appearance.

 

[tensor0910]

This goes against everything I was ever taught, but as soon as you posted this it made sense. Thank you!