From a full

From a full cylindrical glass with a diameter of 8 cm, 1 decilitre of water was poured out. By how many centimetres did the water level in the glass drop?

Final Answer:

h =  2 cm

Step-by-step explanation:

$$\begin{gathered} d=8\text{cm} \\ V=1\text{dl}\to {\text{cm}}^3=1\cdot 100{\text{cm}}^3=100{\text{cm}}^3 \\ r=d/2=8/2=4\text{cm} \\ {S}_1=\pi \cdot r^2=3.1416\cdot 4^2\doteq 50.2655{\text{cm}}^2 \\ V=S_1\cdot h \\ h=V/S_1=100/50.2655=2\text{cm} \end{gathered}$$

Try another example