Asked by Kevin Chau

The height h (in feet) of an underhand volleyball serve can be modeled by h=−16t2+30t+4, where t is the time in seconds. After how many seconds is the ball 16 feet above the ground? Round your answers to the nearest tenth.

The ball is 16 feet above the ground after about
_______
seconds and after about
__________
seconds.
Answered by John
Sub h=16 into the equation and re-arrange to get 0 = ... then factor to solve for the two different times that the height is 16 feet.
hint:
0=-16t^2+30t-12
Answered by kamayah
2 seconds