A cylindrical tank with radius 5m is being filled with water at a rate of $3m^3/min$ How fast is the height of the water increasing?
I know that $$dv/dt = 3$$
And that $$v= \pi r^2 h$$
So I want to find the derivative of h
$$h= \frac {v}{ \pi r^2}$$
$$h' = \frac{3 \pi * 25}{ (\pi * 25)^2 }$$
$h' * v'$
This gives an incorrect answer and I am not sure why.