Question 771188
S(t)=-16t^2+32t+256.

This is an inverted parabola

The vertex has to be calculated to get the height

x= -b/2a

b=32, a=16
x= -32/-32=1

plug x=1 in the equation to get the maximum height.

S(t)=-16(1)^2+32(1)+256.
H= 272