a chemist has an empty cylinder with a height of 30 cm and a cone - shaped flask. the flask has the same…

Explanation:

Step1: Recall volume formulas

The volume formula for a cylinder is $V_{cylinder}=\pi r^{2}h_{cylinder}$, and for a cone is $V_{cone}=\frac{1}{3}\pi r^{2}h_{cone}$.

Step2: Compare volumes

Since the cone and the cylinder have the same - radius ($r$) and the same height ($h = 30$ cm), let the radius of both be $r$ and height be $h$. The volume of the cone $V_{cone}=\frac{1}{3}\pi r^{2}h$, and the volume of the cylinder $V_{cylinder}=\pi r^{2}h$.

Step3: Find the height of water in cylinder

When the water from the full - cone is poured into the cylinder, let the height of water in the cylinder be $h_{1}$. Since the volume of water (volume of the cone) is equal to the volume of water in the cylinder, we have $\frac{1}{3}\pi r^{2}h=\pi r^{2}h_{1}$. Canceling out $\pi r^{2}$ on both sides, we get $h_{1}=\frac{1}{3}h$. Given $h = 30$ cm, then $h_{1}=\frac{1}{3}\times30 = 10$ cm.

Answer:

B. 10 cm