Question 1158962
 h(t)= -16t^2 + 64t +11
the maximum height is at the vertex, and the x value of the vertex is at -b/2a or -64/-32 or +2 seconds.
h(2)=-64+128+11
=75 feet

{{{graph(300,300,-5,5,-20,100,-16x^2+64x+11)}}}