Answer:
t = 4.5 second
Explanation:
A toy rocket travels at an initial velocity of 144 feet per second. The height of the rocket can be modeled by the function as follows :
[tex]h(t)=-16t^2+144t[/tex]
t is time in seconds
We need to find the time when the rocket return to the ground.
When it reaches ground, h(t) = 0
So,
[tex]-16t^2+144t=0\\\\t(-32t+144)=0\\\\t=0\ \text{and} -32t+144=0\\\\t=0\ \text{and}\ t=4.5\ s[/tex]
So, at 4.5 second the rocket will return to the ground.