Chapter 6.6, Problem 19ES

A swimming pool is built in the shape of a rectangular parallelepiped $10\text{ ft}$ deep, $15\text{ ft}$ wide, and $20\text{ ft}$ long.

(a) If the pool is filled to $1\text{ ft}$ below the top, how much work is required to pump all the water into a drain at the top edge of the pool?

(b) A one-horsepower motor can do $550\text{ ft-lb}$ of work per second. What size motor is required to empty the pool in $1$ hour?