Question

the diameter of a cylindrical water tank is 9 ft, and its height is 8 ft. what is the volume of the tank? use the value 3.14 for π, and round your answer to the nearest whole number. be sure to include the correct unit in your answer.

Explanation:

Step1: Find the radius

The radius $r$ of a circle is half of the diameter $d$. Given $d = 9$ ft, so $r=\frac{d}{2}=\frac{9}{2}= 4.5$ ft.

Step2: Use the volume formula for a cylinder

The volume formula for a cylinder is $V=\pi r^{2}h$. Substitute $r = 4.5$ ft, $h = 8$ ft and $\pi=3.14$ into the formula.
$V=3.14\times(4.5)^{2}\times8$.
First calculate $(4.5)^{2}=4.5\times4.5 = 20.25$.
Then $V=3.14\times20.25\times8$.
$3.14\times20.25 = 63.585$.
$V=63.585\times8=508.68$ $ft^{3}$.

Step3: Round the result

Round $508.68$ to the nearest whole number. Since the decimal part $0.68>0.5$, we round up. So $V\approx509$ $ft^{3}$.

Answer:

$509$ $ft^{3}$