The height is modeled by,
[tex]h(t)=-16t^2+128[/tex]Where
t is time in seconds
We want to find the time, t, rocket will be 240 feet above the ground.
So we will substitute 240 into h(t) and find the corresponding value of "t".
The steps are shown below:
[tex]\begin{gathered} h(t)=-16t^2+128 \\ 240=-16t^2+128 \\ 16t^2=112 \\ t^2=7 \\ t=\sqrt[]{7} \end{gathered}[/tex]Square root of 7 is approximately 2.65 seconds.
So,
Answer2.65 seconds