Atrough is 7 feet long and 1 foot high. The vertical cross-section of the trough parallel to an end is shaped like the graph of y = 31 from x = 71 to a: = 1 . The trough is full of water. Find the amount of work in foot-pounds required to empty the trough by pumping the water over the top. Note: The weight of water is 62 pound: per cubic foot. C]