Water reservoir

The reservoir shape of a cylinder has a diameter of 8 m and a height of 2.8 m. The device indicates that the reservoir contains 800 hectoliters of water. Calculate how much % of the volume is used.

Correct answer:

p =  56.8411 %

Step-by-step explanation:

$$\begin{gathered} V_1=800\text{hl}\to {\text{m}}^3=800:10{\text{m}}^3=80{\text{m}}^3 \\ D=8\text{m} \\ h=2.8\text{m} \\ r=D/2=8/2=4\text{m} \\ {V}_2=\pi \cdot r^2\cdot h=3.1416\cdot 4^2\cdot 2.8\doteq 140.7434{\text{m}}^3 \\ p=100\cdot \frac{V_1}{V_2}=100\cdot \frac{80}{140.7434}=56.8411\% \end{gathered}$$

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