Water level

How high is the water in the cylindrical barrel with a diameter of 12 cm if there is a liter of water? Express in cm with an accuracy of 1 decimal place.

Correct answer:

h =  8.8 cm

Step-by-step explanation:

$$\begin{gathered} d=12\text{cm} \\ V=1\text{l}\to {\text{cm}}^3=1\cdot 1000{\text{cm}}^3=1000{\text{cm}}^3 \\ r=d/2=12/2=6\text{cm} \\ V=\pi r^{2}h \\ h=\frac{V}{\pi \cdot r^2}=\frac{1000}{3.1416\cdot 6^2}=8.8\text{cm} \end{gathered}$$

Try another example