Hydrostatic Pressure: Calculate Force on Cylindrical Tank

africanmasks
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Homework Statement


A cylindrical tank, with base radius 9.4 meter, lies on its side and is partially filled with a liquid whose density is \sigma=1260 kilograms per cubic meter. The liquid fills the tank to a maximum depth of 14 meters. Determine the amount of force (in Newtons) exerted on a flat side of the tank.

Homework Equations



F=\sigmadA

The Attempt at a Solution



I need help setting it up.

So far I have:

F= int (from -9.4 to 9.4) (14-y) 2(88.36-y^2)^(1/2)

Is that right? Or should be from 0 to 14?
 
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The pressure is a variable function of the depth. You have to integrate the pressure over the area of the end of the tank.
 
africanmasks said:
I have everything set-up, but I don't know what the depth is. Is it just 14 or y-14?

You need to let the depth be a function of y. You might be able to use y-14, but you will definitely need a y somewhere (finding depth as a function of y can be tricky and was one of the hardest things for me for these kinds of pressure problems since there can be more than one way to set it up).
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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