I have some questions.

1) A circular swimming pool has a diameter of 20 m, the sides are 4 m high, and the depth of the water is 3.5 m. How much work (in Joules) is required to pump all of the water over the side? (The acceleration due to gravity is 9.8 and the density of water is 1000 .)

3) Find the area of the surface obtained by rotating the curve from to about the -axis.