Question

a model rocket is fired straight up from the ground. The heigth of the rocket (in feet) at any time T (in seconds) can be modeled by the equation h= -16t^2+ 128 when will the height of the rocket be 240feets from the ground.

Answer 1

The height is modeled by,

`h(t)=-16t^2+128`

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:

`\begin{gathered} h(t)=-16t^2+128 \\ 240=-16t^2+128 \\ 16t^2=112 \\ t^2=7 \\ t=\sqrt[]{7} \end{gathered}`

Square root of 7 is approximately 2.65 seconds.

So,

Answer2.65 seconds