Work to pump water from a hemispherical tank

[norcal]

Homework Statement

The hemispherical tank shown is full of water. Given that water weighs 62.5 lb/ft3, find the work required to pump the water out of the tank. (the water will be pumped out of a spigot at the top)

Homework Equations

INTEGRAL from 0 to 5 of: pi*(5-h)(25-h^2)dh

The Attempt at a Solution

INTEGRAL from 0 to 5 of: pi*(h^3-5h^2-25h+125)dh

pi*((h^4)/4 - (5h^3)/3 - 12.5h^2 + 125h)

= (3125/12)*pi ft-lb.

This answer is incorrect though...anyone know what I am doing wrong? Thanks.

 

[Dick]

You didn't use the density of water data. How would you incorporate this?