Question

The height of a flare fired can be described as, h=-16t + 60t
T is time and H is height in feet. How long will it take to reach 36 feet

Answer 1

typo
h = -16^2 + 60 t !!!! on earth
happens twice, on the way up and on the way down
36 = -16 t^2 + 60 t
16 t^2 -60 t + 36 = 0
4 t^2 - 15 t + 9 = 0
(4 t - 3)( t - 3) = 0
t = 3/4 on the way up
t = 3 on the way down (but burnt out)

Answer 2

if the flare burns longer than 3 seconds, it will still be burning on the way down.