If $h$ is the water's height, the volume of the water is $V=\pi r^{2} h$. We must find $d V / d t$. Differentiating both sides of the equation gives the following. \[ \frac{d V}{d t}=\square \frac{d h}{d t} \] Submit Skip (you cannot come back)

Step 1 ：The question is asking for the derivative of the volume with respect to time. We know that the volume of the water is given by the formula \(V=\pi r^{2} h\).

Step 2 ：We can differentiate this equation with respect to time to find \(d V / d t\). The radius \(r\) is not a function of time, so it is treated as a constant during differentiation.

Step 3 ：Therefore, the derivative of \(V\) with respect to time is simply the derivative of \(\pi r^{2} h\) with respect to time, which is \(\pi r^{2} \frac{d h}{d t}\).

Step 4 ：Final Answer: The derivative of the volume with respect to time is \(\boxed{\pi r^{2} \frac{d h}{d t}}\).