McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
Study Guide and Review
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Exercise 30 Page 873

Use the formula for the volume of a sphere.

18π cubic centimeters

Practice makes perfect
Cement is poured into the following hemisphere with a diameter of 6 centimeters.
Since the radius is half of the diameter, we get that it is equal to r= 62= 3 centimeters. We are asked to find the volume of the hemisphere, V_\text{hemisphere}. Let's use the formula for the volume of a sphere.
V_\text{hemisphere}=\dfrac{1}{2}\cdot {\color{#FF0000}{V_\text{sphere}}}
V_\text{hemisphere}=\dfrac{1}{2}\cdot {\color{#FF0000}{\dfrac{4}{3}\pi r^3}}
Substitute 3 for r and evaluate
V_\text{hemisphere}=\dfrac{1}{2}\cdot\dfrac{4}{3}\pi ({\color{#0000FF}{3}})^3
V_\text{hemisphere}=\dfrac{1}{2}\cdot\dfrac{4}{3}\pi (27)
V_\text{hemisphere}=\dfrac{4}{6}\cdot \pi (27)
V_\text{hemisphere}=\dfrac{2}{3}\cdot \pi (27)
V_\text{hemisphere}=\dfrac{2}{3}\cdot 27\pi
V_\text{hemisphere}=\dfrac{2\cdot 27\pi}{3}
V_\text{hemisphere}=\dfrac{54\pi}{3}
V_\text{hemisphere}=18\pi
Therefore, the volume of the hemisphere is 18π cubic centimeters.