An iceberg is idealised as a composite solid consisting of a right circular cylinder of radius 1.5 m and height 4 m surmounted by a hemisphere of the same radius. When the iceberg floats in sea water, only one-third of the hemispherical part projects above the water surface, while the entire cylindrical part remains submerged.
Take π=722.
a. (i) Find the total external surface area of the iceberg.
b. (ii) Calculate the area of the iceberg that is in direct contact with sea water.