Answer
(a) $2500ft$
(b) $1000ft$
Work Step by Step
(a) We have $h(x)=10x-0.01x^2=-0.01(x^2-1000x)$ and we know a maximum will happen when
$x=1000/2=500ft$, $h(500)=2500ft$
(b) When the cannonball splash into the water, $h(x)=0$ which gives $x=0, 1000$,
choose $x=1000ft$ for the end point.
