# I don't remember how i did this: "Find fluid force on vertical side of tank where..."

#### Seed5813

##### New member
I don't remember how i did this: "Find fluid force on vertical side of tank where..."

Find the fluid force on the vertical side of the tank, where the dimensions are given in feet. Assume that the tank is full of water. (The weight-density of water is 62.4 pounds per cubic foot.)

So F = (w) int_a^b (h(y)L(y)) dy

w=62.4
a=0
b=8
h(y) = 8-y (the depth)
L(y) = 3/2 (the length between the left and right lines)

I'm reviewing my homework and I don't know how I got L(y) = 3/2 I must have just guessed the slope or something. How would a constant be the length when the distance between the lines is changing?

Sent from my LGLS755 using Tapatalk

#### stapel

##### Super Moderator
Staff member
Find the fluid force on the vertical side of the tank, where the dimensions are given in feet. Assume that the tank is full of water. (The weight-density of water is 62.4 pounds per cubic foot.)

So F = (w) int_a^b (h(y)L(y)) dy

w=62.4
a=0
b=8
h(y) = 8-y (the depth)
L(y) = 3/2 (the length between the left and right lines)

I'm reviewing my homework and I don't know how I got L(y) = 3/2 I must have just guessed the slope or something. How would a constant be the length when the distance between the lines is changing?
As displayed, there is no "vertical side" of the tank. Is there more information? For instance, is there something specifying that, by "vertical side of the tank", they just mean "a point on the side of the conical tank"? Or is the drawing just a representation of the side of a "prism" shape?

When you reply, please include a clear listing of your thoughts and efforts so far, in re-solving this exercise. Thank you!