Water in a cylinder of height 10 ft and radius 4 ft is to be pumped out. Find the work required if

(a) The tank is full of water and the water is to be pumped over the top of the tank.

(b) The tank is full of water and the water must be pumped to a height 5 ft above the top of the tank.

(c) The depth of water in the tank is 8 ft and the water must be pumped over the top of the tank.

I just want to know here.. how I would have to change my setup of the problem to account for each condition.. I get confused on what my limits of integration are..(i think that's what changes here.)

Thanks in advance.