General equation for height, h
h = ut + 0.5gt^2
at t=1s, h = 76 feet
76 = u*1 + 0.5*a*1^2
76 = u + 0.5a
at t=2s, h = 144 feet
144 = u*2 + 0.5*a*2^2
144 = 2u + 2a
72 = u + a
Subtract 2 equations
0.5a = -4
a = -8
u = 80
So the equation,
h(x) = 80t + 0.5*(-8) t^2
h(x) = 80t - 4t^2
