Answer:
8 sec
Step-by-step explanation:
h= -16t² +128t
how many seconds will go by before the rocket's flight last.
That means we need to find time 't' when the rocket's height h(t) = 0
Therefore,
0= -16t² +128t
Solving for 't'
0 = t(-16t + 128)
0 = t OR 0 = -16t + 128
0 = t OR -128 = -16t
0 = t OR -128/-16 = t
0 = t OR 8 = t
t=0 is not possible because this would mean that rocket hasn't left the ground.
Thus, the rocket's flight will last for 8 sec.
