Here the time function is h(t) = [6 + 96t - 16t^2] feet.
The initial height of the ball is 6 feet. That's when t=0. h(0)=[6+0-0] ft = 6 ft.
At t=7 sec, h(t) = [6 + 96t - 16t^2] feet becomes
h(7 sec) = h(t) = [6 + 96(7) - 16(7)^2] feet This produces a large negative number (-106 ft), which in theory indicates that the ball has fallen to earth and burrowed 106 feet into the soil. Doesn't make sense.
Instead, let t=1 sec. Then h(1 sec) = h(t) = [6 + 96(1) - 16(1)^2] feet
=[6 + 96 -16] ft, or 86 ft.
One sec after the ball is thrown upward, it reaches a height of 86 feet. It continues to rise, slowing down, until it finally stops for an instant and then begins to fall towards earth.