a container of the form obtained by revolving the parabola y = 0.75 x^2, 0 <=x<=4, about the y axis is full of water .here x and y are given in meters. find the work done in pumping the water.
A. to an outlet at the top of the tank
B. to an outlet 1 meter above the top of the tank. take weight density = 9000. answers are 384*pi*9800 and 480 * pi * 9800. please explain.