An object, initial moving upward with a speed of 9.50 m/s, experiences a constant acceleration of 1.60 m/s^2 downwards. How much time would it take for it move up to a maximum displacement, come to rest, and then come back down to a position that is 4.00 m above its original position?

Answer key says vf=8.8006 m/s and time 11.4 sec. But I don't know how to get there.

For maximum height, V 2 - U 2 z zas h 27 0 - 9.5 2 - 2*1 6x h 3 h = 28 . 2 m d= h- 4 = 28.2 - 4 = 24.2 m. for this distance, initial velocity, we s. v2 uzz 2as = > V. L - O = 2X 1. 6 X 24. 2 = > V. 2 hhitt = 2 177. Un = 8:8 m/s