5. Volumes of Pyramids and Cones
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Use the formula for the volume of a cone.
About 471.2 cubic inches
Let's analyze the given composite solid.
It consists of two solids.
Now, let's use the formula for the volume of a cone.
| Solid | Left Cone | Right Cone |
|---|---|---|
| Radius | r= 5 | r= 5 |
| Height | h_1= 7 | h_2= 11 |
| Volume | V_\text{left}=\dfrac{1}{3}\pi {\color{#0000FF}{r}}^2{\color{#009600}{h_1}} | V_\text{right}=\dfrac{1}{3}\pi {\color{#0000FF}{r}}^2{\color{#009600}{h_2}} |
| \textcolor{darkorange}{V_\text{left}}=\dfrac{1}{3}\pi({\color{#0000FF}{5}})^2({\color{#009600}{7}})=\textcolor{darkorange}{\dfrac{175\pi}{3}} | \textcolor{darkviolet}{V_\text{right}}=\dfrac{1}{3}\pi ({\color{#0000FF}{5}})^2({\color{#009600}{11}})=\textcolor{darkviolet}{\dfrac{275\pi}{3}} |
To find the volume of the composite solid we will add the volume of the cones. Then we will round our answer to the nearest tenth.
\textcolor{darkorange}{V_\text{left}}={\color{#0000FF}{\textcolor{darkorange}{\dfrac{175\pi}{3}}}}, \textcolor{darkviolet}{V_\text{right}}={\color{#009600}{\textcolor{darkviolet}{\dfrac{275\pi}{3}}}}
Add fractions
Calculate quotient
π ≈ 3.1416
Multiply
Round to 1 decimal place(s)
Finally, we find that the volume of the given solid is about 471.2 cubic inches.