Calculus
posted by Kay .
I need help setting up the equation.
The portion of the graph y = ex
between x = 0 and x = ln 3 is rotated around the y axis to form a container. The container is filled with water. Use n = 4 subintervals and midpoints to approximate the work required to pump all of the water out over the side of the container.(Distance is measured in meters, the density of water is 1000 kg/m3, and use 9.8 m/s2 for g.)
I know you suppose to use the method of disk to find the volume.But then I need to know the work done...
So x=ln(y)
Would it be something like
V=pi*(ln(y))^2*delta y ?
Please help, thanks

whoops the graph is y=e^x

The portion of the graph
y = ex
between x = 0 and x = ln 3 is rotated around the y axis to form a container. The container is filled with water. Use n = 4 subintervals and midpoints to approximate the work required to pump all of the water out over the side of the container. Give your answer in decimal form. 
18898.05075 is the correct answer accepted by Webassign.