The height equation is H = -16t^2 + 32.3t + 5.6.
Substitute 1.5 for t in the equation to determine the height of the ball after 1.5 second.
[tex]\begin{gathered} H=-16(1.5)^2+32.3\cdot1.5+5.6 \\ =-36+48.45+5.6 \\ =18.05 \end{gathered}[/tex]So height is 18.05 feet.