Students need to substitute the value of the radius in the formula V = 4/3 πr^3 to find the volume of the sphere. For example, if the radius of a sphere is 3 units, then the formula V = 4/3 πr^3 becomes V= 4/3π(3)^3.
After simplifications, the final values can be V=36π cubic units or V ≈ 113.1 cubic units. Therefore, the volume of the sphere is 36π cubic units and the volume of the hemisphere is half of 36π, which is 18π cubic units