Since t represents the time and f(t) the height above the ground, we need to substitute t=1.5 i nto the given function f(t),
[tex]f(1.5)=-16(1.5^2)+24(1.5)[/tex]
which gives
[tex]f(1.5)=-36+36=0[/tex]
This means that the ball hits the ground after 1.5 seconds. Therefore, the answer is: The ball is 0 feet above the ground after 1.5 seconds
