Answer:143.60 ft
Step-by-step explanation:
Given
Height of hill [tex]h=80\ ft[/tex]
the launch velocity of the rocket is [tex]u=64\ ft/s[/tex]
At maximum height, the velocity of the rocket is zero
using the third equation of motion [tex]v^2-u^2=2as[/tex]
[tex]\Rightarrow 0^2-64^2=2\times (-32.2)\times s\\\Rightarrow s=\dfrac{64^2}{64.4}=63.60\ ft[/tex]
The maximum height will be [tex]80+63.60=143.60\ ft[/tex]