For each of the following problems, approximate the work with a Riemann Sum. Then write the corresponding integral that arises when you pass to the limit. Use your calculator to find the work done.
5) A tank in the form of a truncated cone is formed by rotating the segment between (2, 0) and (4, 4) around the y-axis. It is filled with sludge (density 80 lbs/ft 3 ). If the sludge is pumped 4 feet upwards into a tank truck, how much work was required?