for the following exercises, find the mass of the two-dimensional object that is centered at the origin.

248. [T] Find the work required to pump all the water out of a cylinder that has a circular base of radius 5 ft and height 200 ft. Use the fact that the density of water is 62 1b/ft3. 249. [T] Find the work required to pump all the water out of the cylinder in the preceding exercise if the cylinder is only half full