A gas station stores its gasoline in a tank under the ground. The tank
is a cylinder lying horizontally on its side. (In other words, the
tank is not standing vertically on one of its flat ends.) If the
radius of the cylinder
is 1 meter, its length is 6 meters, and its top
is 1 meter under the ground, find the total amount of work needed to
pump the gasoline out of the tank.
(The density of gasoline is 673 kilograms per cubic meter; use
.)