A water​ tank, shown to the​ right, is shaped like an inverted cone with height m and base radius m. a. If the tank is​ full, how much work is required to pump the water to the level of the top of the tank and out of the​ tank? Use for the density of water and for the acceleration due to gravity.
b. Is it true that it takes half as much work to pump all the water out of the tank when it is filled to half its depth as when it is​ full? Explain.