Question 1051603
h =-4.9t^2 + 78.4t + 11.3 
h = -4.9(t-8)^2 + 4.9(64) + 11.3
h = -4.9(t-8)^2 + 313.6 + 11.3
h = -4.9(t-8)^2 + 324.9  Good Work
Parabola opening downward V(8, 324.9)
a) maximum height = 324.9m
b) after how many seconds does the flare reach the maximum height: t = 8sec
c) when will the flare hit the ground below? h = 0
0 =-4.9(t-8)^2 + 324.9 
4.9(t-8)^2 = 324.9
(t-8)^2 = 324.9/4.9
t = {{{sqrt(324.9/4.9) + 8 }}}
d) determine the height of the platform: 
h =-4.9t^2 + 78.4t + 11.3 
t = 0, the height of the platform is 11.3m