Toothpaste 80763

Little Jirka wanted to know how much toothpaste was in the tube, so he gradually squeezed it all out and there was a cylinder of toothpaste in the room. Can you guess how long it might have been? Calculate the values: the internal diameter of the paste neck is 6 mm and the volume of the paste is 75 ml.

Correct answer:

x =  265.3 cm

Step-by-step explanation:

$$\begin{gathered} D=6\text{mm}\to \text{cm}=6:10\text{cm}=0.6\text{cm} \\ V=75\text{ml}\to {\text{cm}}^3=75\cdot 1{\text{cm}}^3=75{\text{cm}}^3 \\ r=D/2=0.6/2=\frac{3}{10}=0.3\text{cm} \\ V=\pi r^2\cdot x \\ x=\frac{V}{\pi \cdot r^2}=\frac{75}{3.1416\cdot 0.3^2}=265.3\text{cm} \end{gathered}$$

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