Suppose that a semicircular region with a vertical diameter of length 18 is rotated about that diameter.

Question

Determine the EXACT surface area (in square units) and the EXACT volume (in cubic units) of the resulting solid of revolution.

Find:

A. surface area in units2

B. volume in units3

Answer 1

Diameter = 18 units

Radius = 9 units

Surface area of sphere so generated = 4pi * radius ² = 1018.285 unit²

Volume of sphere so generated = 4/3 ( pi* radius ³) = 3054.857 unit³