A steel cable that weighs 8 lb/ft is used to pull a 500 lb block of concrete from the ground to the top of a 120 ft tall building. Let x be the distance, in feet, from the block to the TOP of the building. Express the work done, as an integral in x. W= )dx Let y be the distance, in feet, from the block to the GROUND. Express the work done, as an integral in y. W= 10 dy