Find the total amount of work required to pump a liquid through the pipe at the top with a weight density of p=10N/ m^3 if the tank below is filled to a depth of 2m.

Solution
For this case we can do the following
V_L= L*w*h = 8*w*delta x
then we can create the following relation:
3/3 = (3-x)/w
w = 3-x
Then replacing in the slice volume we have:
V_L = 8*(3-x)*delta x
The force is given by:
F= rho * V_L = 10 N/m^3 * 8* (3-x)* delta x
Displacement = 2+x
then the total work is given by:
[tex]\int ^3_010\cdot8\cdot(3-x)\cdot(2+x)dx=1080[/tex]If we solve the integral we got:
1080 J