Question 338864
the graph is a downward opening parabola
the maximum height is at the vertex , on the axis of symmetry


the general equation for the axis of symmetry is ___ x = -b / (2a)
___ in this case ___ x = -160 / [2(-16)] = 5


H(5) = -16(5^2) + 160(5) = 400


so the max height is 400 ft and it takes 5 sec to get there


time up equals time down , so the "flight" time is 10 sec