A swimming pool is built in the shape of a rectangular parallelepiped 8 ft deep, 15 ft wide and 15 ft long.

(a) if the pool is filled to 1 ft below the top, how much work is required to pump all the water into a drain at the top edge of the pool? (Use 62.4 lb/ft$^2$ for the weight density of water.)

Work =ft$\cdot$lb.

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

size of motor =hp.