Kairay created a sculpture by forming a hemisphere with a radius of 20 inches and then removing a hemisphere with a radius of 15 inches from it. Calculate the volume of his sculpture. Use 3.14 as an approximation for pi. Round your answer to the nearest whole number.(1 point)

1 answer

The volume of a hemisphere with radius 20 inches can be calculated using the formula
V1 = (2/3) * pi * (20 inches)^3

The volume of a hemisphere with radius 15 inches can be calculated using the same formula
V2 = (2/3) * pi * (15 inches)^3

To find the volume of the sculpture, we need to subtract V2 from V1.
V_sculpture = V1 - V2 = (2/3) * pi * (20 inches)^3 - (2/3) * pi * (15 inches)^3

Calculating this expression using the given approximation for pi, we get
V_sculpture ≈ (2/3) * 3.14 * (20 inches)^3 - (2/3) * 3.14 * (15 inches)^3
≈ 3.14 * (2/3) * (20 inches)^3 - 3.14 * (2/3) * (15 inches)^3
≈ 3.14 * (2/3) * 8000 cubic inches - 3.14 * (2/3) * 3375 cubic inches
≈ 3.14 * (5333.33 - 2250) cubic inches
≈ 3.14 * 3083.33 cubic inches
≈ 9670.83 cubic inches

Rounding this to the nearest whole number, we get the volume of the sculpture as
V_sculpture ≈ 9671 cubic inches. Answer: \boxed{9671}.