Answer:
Explanation:
a)
when is s = 0 ?
0 = t(96 - 16 t)
t = 0 of course, it starts at 0
t = 96/16 = 6 seconds
b)
when is s = 128 (two times, on the way up and on the way down)
128 = 96 t - 16 t^2
8 = 6 t - t^2
t^2 - 6 t + 8 = 0
(t-4)(t-2) = 0
so between 2 seconds and 4 seconds
