Hi,
I'm having problems understanding where to begin with this problem. Could someone here please point me in the right direction?
We are given:
$\displaystyle V=\frac{1}{3}\pi r^2h$
and $\displaystyle h=3r$ so we may write:
$\displaystyle V=\frac{1}{3}\pi r^2(3r)=\pi r^3$
Now, implicitly differentiate with respect to time $\displaystyle t$, then use the values given for $\displaystyle \frac{dr}{dt}$ and $\displaystyle r$ to find $\displaystyle \frac{dV}{dt}$