Answer: 9 s
Explanation:
Given:
h(t) = -16t² + 144t
Find:
time when h=0 They want to know when the rocket hits the ground. This happens when h=0
Solution:
0 = -16t² + 144t >Take out Greatest Common Factor
0 = (-16t )(t - 9) >Set each parenthesis = 0
(-16t ) = 0 and (t - 9)=0 >Solve for t
t = 0 and t = 9 >When the rocket launches t=0 and h=0
Also, t=9 when h=0
t=9 s