A ball thrown vertically upward from the ground. Its distance in feet from the ground in t seconds is s=-16t^2+128t. After how many seconds will the ball be 192 feet feom the grounds in seconds?

SOLUTION:

             s=-16t^2+128t

           192 = -16t^2+128t

           16t^2 - 128t + 192 = 0

           t^2 - 8t + 12 = 0

            (t -2)(t - 6) = 0

 After 2 seconds the ball be 192 feet feom the grounds

Also at the time of return , After 6 seconds the ball be 192 feet feom the grounds